Preheat the oven to 350°F (175°C).

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg and vanilla extract until well combined.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Scoop tablespoon-sized portions of dough onto a baking sheet lined with parchment paper.

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.

Remove from the oven and let cool on the baking sheet for a few minutes before transferring to a wire rack.

In a small saucepan, heat the heavy cream over medium heat until just simmering.

In a bowl, whisk together the egg yolk, granulated sugar, and vanilla extract.

Slowly pour the hot cream into the egg mixture, whisking constantly to prevent curdling.

Return the mixture to the saucepan and cook over low heat until thickened, about 5 minutes.

Once the cookies are cooled, spoon a small amount of the crème brûlée mixture onto each cookie.

Sprinkle brown sugar on top of the crème brûlée layer.

Using a kitchen torch, caramelize the sugar until it forms a crispy top. Alternatively, place under a broiler for a few minutes.

Let cool slightly before serving.