Preheat oven to 350°F. Line a muffin tin with cupcake liners or spray with cooking spray.
In a large zippered plastic bag, combine 1/2 cup granulated sugar and 1 tablespoon cinnamon. Seal and shake to mix.
Open biscuit cans and separate each biscuit. Using kitchen scissors, cut each biscuit into 8 equal pieces.
Drop a handful of biscuit pieces into the cinnamon sugar bag. Seal and shake vigorously until all pieces are completely coated. Repeat in 2-3 batches.
Place exactly 8 coated biscuit pieces into each muffin cup, filling about three-quarters full.
In a medium bowl, mix melted butter with brown sugar and 1 tablespoon cinnamon until well combined.
Drizzle about 2 spoonfuls of the butter mixture over each muffin cup, distributing evenly across all 16 portions.
Bake for 20 minutes until biscuits are puffed, golden brown, and a toothpick inserted in the center comes out clean.
Let cool in the pan for 5 minutes.
While cooling, make the glaze by combining powdered sugar with 1 teaspoon milk in a small bowl. Add more milk gradually until you reach drizzling consistency.
Drizzle glaze over warm mini monkey breads and serve.