Monday, August 11, 2014

Cake of the Week: Bourbon Vanilla Cupcakes with Lemon Curd Filling and Meringue Frosting

I hate to be the bearer of bad (obvious) news, but it's mid-August and summer is almost over. Exactly one year ago today I started grad school, which is crazy. Hallelujah right now for a semester sans pre-session this time around (and best of luck to all you back schooling it up in Boston already!).

I will be making my way back to the great metropolis of Somerville at the end of this month and will be making the absolute most of my summer until then. So far it's been a great one -- there's nothing like summertime-ing/weekend-ing in DC: friends and fun and outside activities, and a bit of work here and there too of course. AND after just one more week of work I'm going on vacation to Turkey!!! So that is awesome and you will likely hear about it here on the blog.

But back to the here and now. Summertime desserts are delicious and I've been on a bit of a lemon kick. So let me present to you my most recent baking innovation, inspired by an afternoon of not wanting to think about North African terrorism, and created for an epic end-of-summer rooftop extravaganza: Bourbon Vanilla Cupcakes with Lemon Curd Filling and Meringue Frosting.

They are super light because there are a lot of egg whites going on here, and super-delicious. These are the kinds of cupcakes you feel totally ok eating multiples of (oh why oh why do I have no more?), so make many if you can. The frosting is magical -- I first made it long long ago for a s'mores cake and called it marshmallow frosting. Now that I'm older and far more sophisticated let's call it meringue though, ok? Ok.

The recipe sounds complex, but it's really just three simple components all put together. My roommate made ice cream last week (oh yeah), and so we conveniently had a lot of egg whites in the fridge. A word of warning though: do not use those egg whites that you buy already cracked in a carton. They are not fresh enough to whip into meringue. Also, you can use bottled lemon juice if you feel so inclined, but then you'll miss out on the zest, which gives the curd a lot of flavor.

Bourbon Vanilla Cupcakes with Lemon Curd Filling and Meringue Frosting

White Cake Ingredients:

  • 1 cup milk, room temperature
  • 6 egg whites
  • 1 tsp vanilla extract
  • 2 tablespoons bourbon
  • 2 1/4 cups cake flour
  • 1 3/4 cups sugar
  • 4 tsp baking powder
  • 1 tsp salt
  • 3/4 cup butter (6 oz), softened

Lemon Curd Ingredients: 

  • 3 large eggs
  • 3/4 cup granulated white sugar
  • 1/4 cup fresh lemon juice (2-3 lemons) (do not use the bottled lemon juice)
  • 3 tablespoons unsalted butter at room temperature
  • 1 tablespoon finely shredded lemon zest

Meringue Frosting Ingredients:

  • 2 large egg whites (about ¼ cup)  
  • ½ cup sugar  
  • ½ tsp cream of tartar  
  • ½ cup water  
  • 2 teaspoons pure vanilla extract 


  1. For the cupcakes: Preheat oven to 350 degrees. Line muffin tins with cupcake liners. 
  2. Combine milk, eggs whites, vanilla, and bourbon in a small bowl with a fork. Set aside.
  3. Combine flour, sugar, baking powder and salt in an electric mixer and mix at slow speed with a paddle attachment. Add butter. Continue beating at slow speed until mixture looks like wet sand (If you’re doing this by hand, sift the dry ingredients together and rub in butter).
  4. Add all but 1/2 cup of milk mixture and beat at medium speed for 1 1/2 minutes. Add remaining milk mixture and beat for an additional 30 seconds, scraping the sides of the bowl if necessary. Do not overmix.
  5. Fill each muffin cup about 3/4 of the way. Bake 25-30 minutes, until toothpick inserted into the center comes out clean.
  6. Let cupcakes cool in the pan for 10 minutes, then turn them out onto a wire rack to cool. 
  7. For the lemon curd: While the cake is cooking, in a small saucepan over medium-low heat, whisk the eggs, sugar, and lemon juice until blended. Cook, stirring constantly (to prevent it from curdling), until the mixture becomes thick (like sour cream or a hollandaise sauce). This will take approximately 10 minutes.
  8. Remove from heat.
  9. Cut the butter into small pieces and whisk into the mixture until the butter has melted. Add the lemon zest and let cool.
  10. The lemon curd will continue to thicken as it cools. Cover immediately with plastic wrap (so a skin doesn't form) and refrigerate for up to a week. 
  11. For the frosting: Put the egg whites in a clean, dry mixer bowl or in another large bowl. Have a candy thermometer (or a meat thermometer can work too) at hand. Put the sugar, cream of tartar and water in a small saucepan and stir to combine.  
  12. Bring the mixture to a boil over medium-high heat, cover the pan and boil for 3 minutes. Uncover and allow the syrup to boil until it reaches 242 degrees F on the candy thermometer (soft ball stage). 
  13. When the syrup is at about 235 degrees F, begin beating the egg whites on medium speed with the whisk attachment or with a hand mixer. If the whites form firm, shiny peaks before the syrup reaches temperature, reduce the mixer speed to low and keep mixing the whites until the syrup catches up.  
  14. With the mixer at medium speed, and standing back slightly, carefully pour in the hot syrup, pouring it between the beater(s) and the side of the bowl. Splatters are inevitable—don't try to scrape them into the whites, just carry on.  
  15. Add the vanilla extract and keep beating the whites at medium speed until they reach room temperature, about 5 minutes.  
  16. You should have a smooth, shiny, marshmallowy frosting. Although you could keep it in the fridge in a pinch, it's really better to use it right now.

  1. Use a sharp paring knife to cut the centers out of each cupcake: cut in a circle at an angle to pop out a little cone. Do with these what you will (aka eat them dipped in the lemon curd as you assemble...I will neither tell nor judge). 
  2. Scoop a spoonful of curd into the holes. 
  3. Frost liberally. 
  4. Enjoy!!