Prepare the Coating Mixtures: In a shallow glass bowl, melt the butter in the microwave on reduced power to prevent splattering. In a separate shallow bowl, thoroughly combine the granulated sugar and ground cinnamon until well mixed.
Cut the Biscuits: Using kitchen shears, cut each refrigerated biscuit into thirds. Place the pieces on a plate, making sure to separate them so they don't stick together as you work through the coating process.
Prepare the Baking Dish: Spray an 8×8 baking dish thoroughly with cooking spray, coating both the bottom and sides. Preheat your oven to 375°F to ensure it's ready when you finish assembling.
Coat the Biscuit Pieces: Using an assembly line approach, take each biscuit piece and dip it first in the melted butter, ensuring it's fully coated. Then roll it in the cinnamon-sugar mixture until completely covered. Place each coated piece in the prepared baking dish, arranging them evenly.
Bake to Perfection: Place the baking dish in the preheated oven and bake for 15-18 minutes, or until the biscuit bites turn a deep golden brown on top. The bites will puff up and the cinnamon sugar will create a delicious caramelized coating.
Prepare the Icing: While the biscuit bites are cooling slightly, mix the confectioners' sugar, milk, and vanilla extract in a small bowl until smooth. If the icing seems too thick, add a few drops of milk; if too thin, add more confectioners' sugar.
Finish and Serve: Drizzle the prepared icing over the slightly cooled biscuit bites. Serve warm for the best taste experience.