Sugar Free Cake Mix Recipes: Coconut-lime Sheet Pan Cake That Tastes Illegal

A zesty, fluffy sheet pan cake with coconut vibes and zero added sugar, made fast from a cake mix and a bright lime glaze.

You know what’s rude? When a “sugar-free” dessert tastes like punishment. This coconut-lime sheet pan cake fixes that problem in one pan, one bowl, and one suspiciously easy method. You get that bakery-style tender crumb, a punchy lime finish, and coconut in every bite. And yes, it starts with a sugar-free cake mix because we’re busy and we like winning.

This is the kind of cake you bring to a party and casually forget to mention it’s sugar-free until people ask for the recipe. It cuts clean, travels well, and feeds a crowd without making you babysit layers. The flavor combo feels tropical but still classic, like key lime pie’s laid-back cousin. If you’ve ever wanted a dessert that tastes like sunshine but behaves like a weekday meal prep, welcome home.

What Makes This Recipe So Good

Sheet pan = maximum payoff. You get big-cake energy with minimal effort. One bake, one cool, one glaze, done.

Coconut + lime is a cheat code. Coconut brings richness and aroma, lime brings brightness and snap. Together they taste fancy, even though the base is a mix.

Moisture insurance, built in. Greek yogurt (or sour cream) plus coconut milk keeps the cake tender for days. No dry, crumbly “diet cake” situation.

It’s customizable without getting complicated. Want more tang? Add zest. Want more coconut? Toast it. Want it dairy-free? Easy swaps.

Ingredients

• Sugar-free yellow or vanilla cake mix (one standard box, about 15–16 oz)
• Eggs (3 large)
• Coconut milk (1 cup, canned or carton; full-fat tastes richest)
• Neutral oil (1/3 cup avocado oil, light olive oil, or vegetable oil)
• Plain Greek yogurt (1/2 cup; or sour cream)
• Lime zest (1 to 2 tablespoons, from 2 to 3 limes)
• Fresh lime juice (3 tablespoons for batter, plus 2 to 3 tablespoons for glaze)
• Unsweetened shredded coconut (3/4 cup, plus extra for topping)
• Baking powder (1 teaspoon, optional but helpful for lift depending on mix)
• Salt (1/4 teaspoon, optional if your mix is low-salt)

For the lime glaze (choose one option):

• Powdered sugar-free sweetener (1 to 1 1/2 cups, like powdered erythritol/monk fruit blend)
• Fresh lime juice (2 to 3 tablespoons)
• Vanilla extract (1/2 teaspoon, optional)
• Coconut extract (1/8 teaspoon, optional; go easy or it tastes like sunscreen)

Optional toppings:

• Toasted coconut for crunch
• Thin lime slices or extra zest
• Whipped topping (sugar-free if desired)

Instructions

1. Heat the oven and prep the pan. Preheat to 350°F. Grease a 12×17-inch sheet pan (half-sheet) or line it with parchment. If you use a 9×13-inch pan instead, expect a thicker cake and a longer bake.

2. Mix the wet ingredients first. In a large bowl, whisk eggs, coconut milk, oil, and Greek yogurt until smooth. This step prevents random yogurt lumps from photobombing your crumb.

3. Add the flavor boosters. Stir in lime zest, lime juice, and shredded coconut. Take a second to smell it. This is the “I’m definitely making something good” moment.

4. Bring in the mix. Add the sugar-free cake mix (plus baking powder and salt if using). Stir until just combined. Don’t overmix; you’re baking cake, not training for a whisking competition.

5. Spread and level. Pour batter into the prepared pan and spread into an even layer. A small offset spatula helps, but a spoon and mild determination works too.

6. Bake until set. Bake 14 to 18 minutes for a half-sheet, or until the center springs back when lightly pressed and a toothpick comes out mostly clean. Sugar-free sweeteners can brown differently, so trust the texture more than the color.

7. Cool before glazing. Let the cake cool in the pan for 15 minutes, then cool completely. If you glaze while warm, it melts and disappears like your weekend plans.

8. Whisk the glaze. In a bowl, whisk powdered sugar-free sweetener with lime juice until thick but pourable. Add vanilla or a tiny splash of coconut extract if you want extra coconut-lime drama.

9. Glaze and finish. Drizzle or spread glaze over the cooled cake. Sprinkle with toasted coconut and extra lime zest. Slice into squares and pretend you didn’t just make a whole sheet cake on a random Tuesday.

How to Store

Room temperature: If your kitchen isn’t hot and humid, store the cake covered for up to 2 days. The glaze helps lock in moisture, so it holds up nicely.

Refrigerator: For longer storage, cover tightly and refrigerate up to 5 days. The coconut flavor stays strong, and the lime stays bright. Let slices sit at room temp for 15 minutes before serving for the softest texture.

Freezer: Freeze individual slices for up to 2 months. Wrap each piece in plastic wrap, then place in a freezer bag. Thaw overnight in the fridge or on the counter for about an hour.

Benefits of This Recipe

It’s fast, but it doesn’t taste fast. You get a party-worthy dessert without the whole “three bowls, two mixers, and regret” situation.

Built for sharing. A sheet pan cake feeds a crowd, cuts clean, and travels without leaning like a sad layer cake.

Lower sugar, still satisfying. Using a sugar-free mix and glaze keeps added sugar down while still delivering big dessert vibes. FYI, always check labels since brands vary.

Bright flavor = less need for sweetness. Lime zest and juice give you intensity, so the cake feels bold even with less sugar.

Pitfalls to Watch Out For

Overbaking is the #1 enemy. Sheet cakes bake fast. Pull it as soon as the center springs back; a dry sugar-free cake is a personal betrayal.

Too much coconut extract. A tiny amount can enhance. A larger amount can taste like a candle aisle. Keep it at 1/8 teaspoon or skip it.

Grainy glaze. Some powdered sugar-free sweeteners can feel gritty. Sift it first and whisk longer than you think you need. If it still feels grainy, let it sit 5 minutes, then whisk again.

Using bottled lime juice. Fresh lime juice tastes sharper and cleaner. Bottled works in a pinch, but IMO it flattens the “wow” factor.

Pan size confusion. A half-sheet pan gives you the classic thin, snackable squares. A 9×13 will be thicker and needs extra bake time, so watch closely.

Mix It Up

Key lime version: Swap regular limes for key limes if you can find them. Use extra zest because key limes are smaller but mighty.

Piña colada vibe: Add 1/2 cup finely chopped pineapple (well-drained) and reduce coconut milk by 2 tablespoons to avoid a soggy cake.

Almond-coconut twist: Add 1/2 teaspoon almond extract to the batter and top with toasted sliced almonds. It tastes like a fancy bakery bar cookie’s glow-up.

Dairy-free option: Use a dairy-free yogurt and coconut milk. Check your cake mix ingredients to keep it fully dairy-free.

Extra tang, less sweet: Mix a spoonful of lime zest into the glaze and keep the glaze thin. You’ll get a sharper citrus bite that balances the coconut.

FAQ

Is sugar-free cake mix actually sugar-free?

Most “sugar-free” mixes have no added sugar, but they often contain sweeteners and still have carbs. Always read the nutrition label and ingredients to match your goals.

Can I make this without eggs?

Yes, but texture will change. Try using a commercial egg replacer or 3 “flax eggs” (3 tablespoons ground flaxseed mixed with 9 tablespoons water, gelled). Expect a slightly denser crumb.

What if I only have a 9×13-inch pan?

It works. The cake will be thicker and needs more time, usually 22 to 30 minutes depending on your oven. Start checking at 20 minutes and remove when the center springs back.

Can I use sweetened shredded coconut?

You can, but it defeats the sugar-free angle and makes the cake noticeably sweeter. Unsweetened coconut gives you the coconut flavor without turning it into candy.

Why does my glaze “melt” into the cake?

The cake was still warm or the glaze was too thin. Cool the cake completely and thicken the glaze with more powdered sweetener until it drizzles slowly.

How do I make it more moist?

Use full-fat coconut milk and don’t skip the Greek yogurt or sour cream. Also, pull the cake as soon as it’s done; extra minutes in the oven matter a lot with sheet cakes.

Does this taste like coconut first or lime first?

It hits lime first because the zest and glaze lead, then coconut follows with a creamy finish. If you want more coconut-forward flavor, add a bit more shredded coconut and a tiny touch of coconut extract.

Wrapping Up

This coconut-lime sheet pan cake proves you can go sugar-free without going joy-free. You get bright citrus, mellow coconut, and a soft, bakery-style bite with almost suspicious ease.

Make it for potlucks, birthdays, or that random weeknight when you want dessert but not a whole production. Slice it, stash it, and enjoy having a cake that behaves like a snack. And if someone says “Wait, this is sugar-free?” just nod like it’s no big deal.