Preheat oven to 350°F degrees. Thoroughly grease a muffin tin with butter. Whisk together the dry ingredients. Stir in the milk, vanilla and butter.
Scoop the batter into the greased muffin cups, filling each cup with 2 tablespoons of batter. Make sure the cups are no more than half full. Bake for 20 minutes.
While the cake bites are baking, combine the topping ingredients in a large glass measuring cup or bowl. Melt in the microwave for 1 minute, until the butter has melted and the ingredients whisk together smoothly.
Remove the cake bites from the oven after they have baked for 20 minutes and spoon the topping across them. Bake an additional 8-10 minutes until the cinnamon layer is bubbling. Let cool a few minutes before carefully removing from the pans. Enjoy!