01 -
Preheat the oven to 350°F (175°C). Coat a 9x13-inch baking dish with baking spray.
02 -
Prepare the white cake mix according to package instructions. Pour batter into the prepared baking dish and bake, watching closely as it may finish several minutes earlier than recommended. Allow the cake to cool until slightly warm to the touch.
03 -
Using the handle end of a silicone or wooden spatula, poke holes evenly across the cake approximately ½ inch apart, while the cake is still slightly warm.
04 -
Combine butter, light brown sugar, cinnamon, vanilla extract, and sweetened condensed milk in a heat-safe bowl. Whisk to combine, then microwave on high for 1 minute, stir, and repeat once more. Continue microwaving in 30-second intervals until sugar lumps are dissolved.
05 -
Slowly ladle the warm filling mixture evenly over the entire surface of the cake, allowing it to seep into the holes.
06 -
Using a stand or handheld mixer on medium speed, cream together softened butter and cream cheese until smooth. Gradually add clear vanilla flavoring, half and half, and powdered sugar, ½ cup at a time, mixing on low speed to incorporate. Increase speed to medium and beat until frosting is smooth and fluffy.
07 -
Spread the frosting evenly over the filled cake using a silicone spatula or offset knife. Serve immediately or chill before serving.