Preheat oven to 400°F. Line sheet pan with parchment paper and set aside.
Break an egg into a small bowl and add 1 tablespoon of water. Whisk to combine and set aside.
1 egg + 1 tablespoon water
Slightly roll puff pastry dough out into a 16 x 10" rectangle. Cut puff pastry into 48 (1.5") squares.
1 sheet puff pastry dough,
Place 24 puff pastry squares on prepared pan. Layer a second puff pastry square on each with the remaining 24 puff pastry squares and brush with egg wash. Bake puff pastry squares for 15 minutes or until golden brown. Remove from oven and let cool.
Place one slice of brie on top of puff pastry and top with 1 teaspoon of cranberry sauce. Garnish with thyme. Serve at room temperature.
1 cup cranberry sauce, 4 ounces Brie cheese,
The puff pastry squares can be made ahead of time, just cool completely and store in an airtight container.If you are using a can of cranberry sauce, make sure it is whole berry sauce.