In a large mixing bowl, cream together butter and granulated sugar until fluffy, about 3-4 minutes. Add eggs and vanilla extract, blending until fully incorporated. Gradually mix in flour and baking powder until dough forms.

Cover the cookie dough with plastic wrap and refrigerate for at least 30 minutes to firm it up.

Preheat oven to 350°F (175°C). Scoop dough onto a lined baking sheet, spacing them 2 inches apart. Bake for 12 to 15 minutes until edges are golden.

In a saucepan over medium heat, combine heavy cream and vanilla extract. In a bowl, mix cornstarch with a little cold cream, then stir into simmering cream until thickened, about 3-5 minutes. Cool completely.

Once cookies are cooled, pipe or spoon vanilla pastry cream generously on top of each cookie.

Sprinkle a thin layer of brown sugar over the cream, then caramelize using a kitchen torch or under a broiler for about 1-2 minutes.

Allow the cookies to sit for a few minutes until the sugar hardens. Enjoy your delightful Creme Brûlée Cookies!