Recipe: Low-Calorie Key Lime Bars With Vanilla-Bean Whipped Cream

This citrusy sweet treat bursts with flavor without breaking the dietary bank.

This key lime bar recipe bursts with flavor without overloading on calories and fat. Photograph by Ali Eaves.

Each year, local dietitian Colleen Gerg takes a group to the Canyon Ranch health resort in Tucson, which has a spa, fitness activities, and cooking classes. She shared with us one of her favorite dessert recipes from the resort.

“It’s a lovely, seasonal, satisfying, refreshing dessert that doesn’t break the dietary bank in terms of calories or fat,” she says. Sign us up.

We went through about 20 Key limes to get all of the juice and zest required for this recipe, and the flavor really shines through. Using Greek yogurt in the whipped topping is a genius move–it not only lightens it up, it also adds an unexpected tang that goes perfect with the Key lime.

Yield: 32 servings

Per serving nutrition: 150 calories, 20 grams carbohydrates, 7 grams fat, 3 grams protein.


For the crust:
2/3 cup unsalted butter, room temperature
1/3 cup cane sugar
1 tablespoon Key lime zest
1 2/3 cups all-purpose flour

For the filling:
1½ cups cane sugar
¼ cup all-purpose flour
½ teaspoon aluminum-free baking powder
5 whole eggs
3 tablespoons Key lime zest
2/3 cup freshly squeezed Key lime juice
1½ teaspoons pure vanilla extract

For the whipped topping:
¾ cup heavy cream
¾ cup nonfat Greek yogurt
1/3 cup cane sugar
1 vanilla bean, scraped


1) Preheat oven to 350 degrees.

2) In a food processor, blend together butter, 1/3 cup sugar, and 1 tablespoon lime zest. Gradually add flour to form soft crumbs. Press crumbs evenly into a 9-by-13-inch baking pan to form a crust. Bake for 15 minutes.

3) In a small bowl, stir together 1½ cups sugar, ¼ cup flour, and baking powder.

4) In a large mixing bowl, beat eggs well using a handheld mixer. Gradually add flour-sugar mixture to eggs. Stir in 3 tablespoons lime zest, lime juice, and vanilla extract. Pour lime mixture over baked crust. Return to oven and bake for 20 minutes or until top and sides are light brown.

5) In a medium bowl, using a handheld mixer, mix all whipped topping ingredients until fluffy.

6) Allow bars to cool. Cut into 32 squares. Serve each bar topped with 1 tablespoon whipped topping.

Colleen Gerg, RD, is a nutrition advisor at Privia Health, a certified personal fitness trainer, and a nutrition consultant.