Heat the oven to 400F and grease a 24-cup mini muffin tin.
Unfold the cold pastry on a lightly floured counter and cut into 24 squares. Work quickly to keep it cold so it puffs without turning greasy.
Press one square into each cup, letting the corners stick up. Brush the exposed corners with the egg wash.
Put a brie cube in each cup and top with about half a teaspoon of jam. Do not overfill; it can bubble over and stick to the pan.
Bake 16 to 18 minutes until deeply golden and puffed. Press a fresh raspberry into each while still hot, then finish with almonds, thyme, and flaky salt. Cool 5 minutes before lifting them out.