Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper or use a silicone mat. If using a mini muffin pan, lightly spray with oil to prevent sticking.
Roll the crescent roll dough into a single sheet about 12 long and 8 wide. Lightly flour the surface if needed to avoid sticking. Pinch together any seams in the dough to form a tight sheet.
Cut the dough into 24 equal-sized squares using a 6×4 grid.
Place a small cube of brie (about 1 cubic centimeter) and 1/2 teaspoon of cranberry sauce in the center of each dough square.
Fold opposite corners of each dough square to the center and pinch together to seal.
Transfer the bites to the prepared baking sheet or mini muffin pan.
Bake for 11-13 minutes, or until the bites turn golden brown. Some cheese may melt out, but you can scoop it back in while hot or serve as is.