Cinnamon Cocoa Swirl Coffee Cake

Preheat the oven to 350 F.

In a medium bowl, whisk together the melted butter, eggs, egg yolk, granulated sugar, milk, and vanilla. Set aside.

Into the wet ingredients, sift the salt, baking powder, and flour. Mix until just combined. Pour half of the cake batter into a parchment lined 9″x13″ baking pan. Set aside.

In a small bowl, mix together the brown sugar, cocoa powder and ground cinnamon. Sprinkle the cinnamon cocoa mixture over the cake batter and gently spread it to the edges. Drizzle the melted butter over the cinnamon cocoa mixture.

Pour and spread the remainder of the cake batter over the cinnamon cocoa layer. Using a sharp knife, gently swirl the cinnamon cocoa layer into the cake batter by placing the knife upright in the cake beginning in one corner, and gently dragging and lifting the knife in different places. Do not over swirl.

Bake for 45 to 50 minutes, or until lightly browned on top and a toothpick inserted in the center comes out clean. Remove from the oven and cool on a wire rack.

Once cooled, mix the icing (powdered) sugar and milk in a small bowl until smooth. Drizzle over the cooled cake.