In a large bowl, stir together the ingredients of the jar. Add remaining ingredients; beat on medium speed of mixer 2 minutes. Pour batter into prepared pan.
Bake 35-40 minutes or until wooden pick inserted in center comes out clean. Let cool in pan on wire rack.
Combine cream cheese and powdered sugar, thin with milk to desired consistency. Invert cake on to serving plate. Top with glaze
Notes
The jar of cake mix referred to in the recipe is our homemade Chocolate Cake Mix in a Jar.To prepare the jar, layer the ingredients in order in a 1 quart mason jar and attach the baking instructions (printable version here):