Last year I offered my baking services to the Sacramento Children’s Chorus and pledged to bake a dessert each month for the highest bidder in a silent auction. I’ve actually loved fulfilling my commitment because the winner has requested some desserts that are not in my regular arsenal. This month, he requested a key lime pie. As I set out to baking said pie today, I looked around my kitchen. I had lime juice, zest, and enough whipped cream topping to act as frosting!
And the Key Lime Cupcake was born.
I wanted this cupcake to be super light, so I decided on a white cake as the base. This also work well since I only used egg yolks for the key lime pie. Yay to me for being efficient with my ingredients! The white cake, kicked up a notch with lime juice and zest, turned out fluffy and cloud-like. Because of this, I’m really glad I decided to use a whipped cream topping. Anything else, like a butter cream or cream cheese frosting, would be so heavy I swear these little cakes would collapse.
With the frosting, I’m trying something new: stabilized whipped cream. I found instructions for it here and it claims that the addition of the gelatin adds a bit more body and prevents the melting of the whipped cream as the cakes sit and wait to be eaten. Because I’ll be taking these to share with co-workers and fellow volunteers tomorrow, I think that this whipped cream was the perfect choice.
Key Lime Cupcake
1 c. cake flour
1/2 tsp. baking powder
1/4 tsp. baking soda
1/4 tsp. salt
1/4 c. butter (or shortening) softened
2/3 c. sugar
1/2 tsp. vanilla
2 egg whites, room temperature
2/3 c. milk
1 tbsp. lime juice
1 tsp. lime zest
Preheat the oven to 350 degrees and line your cupcake pan (regular or mini) with liners.
In a measuring cup, measure out your milk. Pour in the lime juice and stir. Let the milk mixture sit while you mix the batter together. This will create a sour milk that you can use just like buttermilk.
In a medium bowl, sift together the flour, baking powder, baking soda, and salt. Set aside.
In a large bowl, cream the butter until soft. Add the sugar and vanilla and cream until light and fluffy. Add the egg white one by one until just combined.
Alternate adding the flour mixture and the soured milk until both are combined. Fold in the lime zest to distribute evenly. (At this point I added a teeny tiny bit of green food coloring to give the cake a slight color, but this is optional).
Fill cupcake liners 2/3 full. Bake for 16-20 minutes (full sized) or 9-12 minutes (mini), or until a toothpick inserted in the center comes out clean.
1 tbsp. + 2 1/2 tsp. cold water
1/2 tsp. vanilla
1/2 tsp. unflavored gelatin
1 c. cold heavy cream
3 tbsp. powdered (confectioners) sugar
In a small bowl, whisk together the cold water, vanilla extract and gelatin until smooth. Let sit for 5-10 minutes. Microwave on high until the gelatin is just dissolved, about 5-10 seconds, no longer–the goal is just to melt the gelatin granules, not heat the mixture too much.
Pour the cream into a medium bowl or the bowl of an electric mixer. Add the melted gelatin mixture and confectioners’ sugar and whisk to blend. Refrigerate for 10-15 minutes or until the cream begins to thicken just a touch. Whip to firm peaks with handheld beaters or a stand mixer. Use immediately as a frosting for your cupcakes.