Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large mixing bowl, beat together the softened butter, granulated sugar, and brown sugar using an electric mixer until the mixture is light and fluffy (about 3-4 minutes).

Add the egg and vanilla extract to the butter mixture, and continue to beat until thoroughly combined.

Slowly add the flour mixture to the wet ingredients, mixing on low speed until just combined.

In a small saucepan, heat the heavy cream over medium heat until just bubbling (do not boil).

Remove from heat and whisk in the cornstarch until smooth. Allow to cool slightly.

Gently fold the cream mixture into the cookie dough until well combined.

Using a cookie scoop or tablespoons, drop dough onto prepared baking sheet, spacing 2 inches apart.

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

Remove from oven and cool on baking sheet for 5 minutes before transferring to a wire rack.

Once cookies are cooled, sprinkle 1 teaspoon of granulated sugar on top of each cookie.

Using a kitchen torch, caramelize the sugar on top until it melts and forms a crispy layer. If no torch, broil carefully for a few seconds.

Allow caramelized sugar to cool and harden before serving.