1½ cups Kamut flour
1½ cups all purpose flour
¾ cup butter, softened
¾ cup packed brown sugar
2 tsp baking soda
1 tsp salt
1½ cups buttermilk
1 tsp vanilla
¼ cups + 2 Tbsp unsweetened
1 cup white chocolate chips
3 cups confectioners’ sugar
1 cup butter, softened
1 Tbsp buttermilk
1 tsp vanilla extract
Preheat oven to 350°F, coat two baking sheets with butter or line with parchment paper.
In a large mixing bowl, use an electric mixer on medium speed mix ¾ cups butter and brown sugar until well blended, add eggs, one at a time, until smooth.
In a separate bowl, mix together flour, baking soda and salt, set aside. In a 2 cup liquid measuring cup, stir together buttermilk and vanilla.
Add half the flour mixture to the butter mixture and mix on medium speed until smooth, scrape sides with rubber spatula. Add half the buttermilk mixture and mix until smooth, repeat with remaining flour and buttermilk and mix until smooth.
Split the batter in half (we just eyeballed it,) mix cocoa powder into half of batter with electric mixer, in other half add white chocolate chips and fold into batter with spatula.
Drop 1 Tbsp portions of dark chocolate batter onto baking sheets, leaving 2 inches between to allow for spreading. Bake 13 minutes, until puffed but still soft when touched. Leaves cakes on baking sheet for 3 minutes, then set onto wire cooling racks for 15–20 minutes. Repeat with white chocolate batter.
Prepare icing while cakes bake and cool. In a large bowl, cream butter and vanilla on medium speed. Add half the confectioners’ sugar on low until combined, then on high until creamy, add remaining confectioners’ sugar and mix again, scraping down sides.
Spoon or pipe icing onto flat side of dark chocolate cake and top with white chocolate cake. If the whoopie pies don’t sit straight, cut off a small piece of the bottom cake before assembling.