01 -
Heat your oven to 350°F and spray a 9 x 13 baking dish with baking spray. Make the cake according to the box directions. Watch closely as these cakes often finish baking before the time on the box suggests. Let the cake cool until it's just slightly warm to touch.
02 -
Using the handle end of a silicone spoon, spatula, or wooden spatula, poke holes all over the cake, spacing them about ½ inch apart. Doing this while the cake is still slightly warm helps prevent the cake from tearing.
03 -
In a heat-safe bowl, mix 5 tablespoons butter, brown sugar, cinnamon, vanilla extract, and sweetened condensed milk. Heat in microwave for 1 minute, stir, then heat another minute and stir again. Keep heating in 30-second bursts until all sugar lumps are gone and mixture is smooth.
04 -
Carefully pour or ladle the warm cinnamon mixture evenly over the cake, making sure to fill the holes. Tap the pan gently on the counter to remove air bubbles and help the filling settle into the holes completely.
05 -
Using a mixer, cream together the 8 tablespoons of softened butter and cream cheese until smooth. Scrape down the bowl, then mix in the clear vanilla and half and half. Gradually add the powdered sugar ½ cup at a time, mixing until smooth and creamy.
06 -
Spread all the frosting over the cake using a silicone spatula for a smooth finish. Store any leftovers in an airtight container.