Mix cake mix, cinnamon, plus ingredients to make the according to package directions. Bake in a greased and floured 9x13 pan. Cool completely.
Mix together sweetened condensed milk, evaporated milk, half and half and cocoa powder. Poke holes in cake and slowly pour milk mixture over cake. Cover and refrigerate overnight.
When ready to serve, whip together heavy cream, powdered sugar and vanilla extract. (I chill my mixing bowl in the freezer for 5-10 minutes before adding the cream and sugar). Whip at high speed for 1-2 minutes. Spread over cake and top each slice with a cherry