In a medium saucepan, heat whole milk over medium heat until steaming but not boiling. In a separate bowl, whisk together egg yolks, granulated sugar, a pinch of salt, vanilla bean paste, and cornstarch. Gradually add the hot milk mixture to the egg mixture, whisking continuously. Pour the mixture back to the saucepan and cook on medium-low heat for 8-12 minutes, stirring constantly until thickened. Stir in unsalted butter and transfer to the fridge to chill.

Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper. Combine all-purpose flour, baking powder, and a pinch of salt in a mixing bowl. In another bowl, cream together unsalted butter and granulated sugar until light and fluffy. Beat in the egg and vanilla extract. Gradually incorporate the dry ingredients until just mixed and a dough forms.

Using a large cookie scoop, portion out the cookie dough and roll each ball in granulated sugar to coat. Place them on the prepared baking sheets, spacing them about 2 inches apart. Gently flatten each dough ball with your palm to create a slightly thicker disk.

Bake the cookies for 9-10 minutes or until the edges are lightly golden. Remove them from the oven and let cool on the baking sheet for about 5 minutes before transferring to a wire rack.

Once the cookies are completely cool, take the chilled pastry cream from the fridge and use a piping bag to pipe a generous dollop onto the center of each cookie. Sprinkle an even layer of granulated sugar over the pastry cream.

Using a kitchen torch, carefully caramelize the sugar on top of the pastry cream until it turns golden brown. If you don’t have a torch, place the assembled cookies under a broiler for a few seconds, being vigilant to prevent burning!

Allow the brûléed cookies to sit at room temperature for about 10 minutes before serving.