Step 1: Make the Cookie Dough

1. In a large mixing bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy (about 2-3 minutes).
2. Beat in the eggs, one at a time, followed by the vanilla extract.
3. In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Avoid overmixing to keep the cookies tender.
4. Cover the dough and refrigerate for at least 30 minutes to prevent spreading during baking.

Step 2: Bake the Cookies

1. Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Using a cookie scoop or tablespoon, portion out the dough into 1.5-inch balls and place them 2 inches apart on the prepared baking sheet.
3. Press the center of each dough ball with your thumb to create a small indent (this is where the custard will go).
4. Bake for 10-12 minutes, or until the edges are lightly golden. The centers will still look slightly underbaked—that’s okay!
5. Remove the cookies from the oven and gently reinforce the indent with the back of a spoon while they’re still warm. Let the cookies cool completely.

Step 3: Make the Custard Filling

1. In a small saucepan, heat the heavy cream over medium-low heat until it just begins to simmer (don’t let it boil).
2. In a bowl, whisk together the sugar and egg yolks until pale and slightly thickened.
3. Slowly pour the hot cream into the egg mixture, whisking constantly to temper the eggs.
4. Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens enough to coat the back of a spoon (about 5 minutes).
5. Remove from heat and stir in the vanilla bean paste. Let the custard cool slightly before transferring it to a piping bag.

Step 4: Fill the Cookies

1. Pipe a small amount of custard into the indent of each cooled cookie. Smooth the tops with the back of a spoon if needed.
2. Chill the filled cookies in the refrigerator for at least 30 minutes to set the custard.

Step 5: Caramelize the Sugar

1. Just before serving, sprinkle about 1 teaspoon of granulated sugar over the custard on each cookie.
2. Use a kitchen torch to caramelize the sugar until it turns golden and forms a crisp shell. If you don’t have a torch, place the cookies under a broiler for 1-2 minutes, watching carefully to avoid burning.
3. Let the sugar cool for 1-2 minutes before serving.