Ingredients
2 1/2 c. all-purpose flour
1 c. granulated sugar
1 tsp. baking soda
1/2 tsp. salt
1 1/2 sticks unsalted butter, sliced into chunks
2 large eggs
2 egg yolks
2 tsp. vanilla extract
2/3 c. buttermilk
1/4 c. cocoa powder
1/3 c. granulated sugar
2/3 c. brown sugar
1 1/2 tsp. cinnamon
1/4 tsp. salt
2 sticks butter, melted
1 1/2 c. flour
1/4 c. chocolate chips
1/4 c. mini marshmallows
Preparation
Step 1Preheat the oven to 325 degrees F. Butter a loaf pan.Step 2Make batter: In a large bowl, mix flour, sugar, baking soda, and salt. Beat in butter, one piece at a time, until pea-sized crumbles form. Add the eggs and yolks, buttermilk, vanilla extract, and cocoa powder. Beat until smooth, about 2 minutes more.Step 3Make the streusel: In a large bowl, combine sugar, brown sugar, cinnamon, salt, butter, flour, and chocolate chips. Once combined, mix with your hands until crumbles form. Top batter with streusel.Step 4Bake for 40 minutes, then scatter with mini marshmallows. Continue baking for 15-20 minutes more, or until a toothpick inserted into the center comes out clean. Let cool completely.
