Open the can of biscuits and cut each biscuit into fourths. Preheat oven to 350 degrees. Prepare pan by spreading 2 Tbsp. melted butter across your monkey bread mold using a napkin.
Add 1 egg and 1 Tbsp skim milk to a bowl and scramble.
Fully coat all biscuit pieces with egg/milk mixture. I like to use a fork to stir them in the egg/milk mixture to allow the egg mixture to drain off as I scoop it out.
Next, roll the coated biscuit pieces in cinnamon and sugar. Fully turn to coat all sides with the cinnamon sugar. Add the first layer of biscuit pieces flat against the bottom of the buttered monkey bread mold (this will ensure a more even top to the monkey bread). Continue to layer the biscuit pieces into the monkey bread mold until all are layered in. After the first layer, the pieces can be simply be dropped in the pan because they will expand and fill in to each other during the bake time.
Cover monkey bread mold with foil and bake in a oven preheated to 350 degrees for 40 minutes, remove foil and bake for another 15 minutes to get a slight crusty bottom. Remove the pan from the oven and allow to cool about 10-15 minutes. I prepare the frosting during this cooling time by adding together 1 c. powdered sugar, 1/2 tsp. vanilla, 4 Tbsp. melted butter, and 1 Tbsp. skim milk in a bowl. Blend with a hand blender for 1 minute to dissolve all the powdered sugar chunks and make a smooth homemade frosting.
Run a butter knife along the edge to ensure the monkey bread will come out easily. Flip it upside down on a plate to remove it from the baking dish and frost it while still hot so the frosting drips down the sides and center of the monkey bread. Serve immediately.