Separate each biscuit into 2 layers. Wrap a biscuit layer around a slice of apple, stretching the biscuit slightly to overlap, and seal on the bottom. Place the wrapped slices, sealed side down, in a 9 × 12 × 2-inch casserole dish. Pour the hot sugar mixture over the apple slices. Mix the remaining ¼ cup sugar with the cinnamon and sprinkle the mixture over the tops of the wrapped apples. Bake for 35 minutes, or until golden brown.