This rich, ultra-moist chocolate cake is layered with a decadent creamy chocolate frosting, combining deep cocoa flavor, a hint of cinnamon, and tender crumb for a show-stopping dessert that melts in your mouth.
Grease and flour three 9-inch cake pans. In a medium bowl stir together flour, cocoa powder, baking soda, salt, and cinnamon; set aside.
In a large bowl beat butter on medium speed of electric mixer for 30 seconds; beat in brown sugar until well blended. Add eggs one at a time, beating well after each addition. Beat in vanilla. With mixer on low speed, add dry ingredients alternately with sour cream, beginning and ending with dry ingredients.
Stir in the hot water; beat at low speed just until blended.
Pour into prepared pans. Bake in a preheated 350°F oven for 30 to 35 minutes or until a toothpick inserted in center of cakes comes out clean. Cool in pans 10 minutes on wire racks. Remove from pans and cool completely.
To assemble, place one cake layer top side down on platter. Spread top with a generous ½ cup Creamy Chocolate Frosting. Repeat with another cake layer and generous ½ cup frosting. Top with remaining cake layer, top side up. Frost top and sides of cake with remaining frosting.