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

In a large mixing bowl, add the softened unsalted butter and granulated sugar. Beat on medium speed until light and fluffy.

Add the vanilla extract and the large egg. Mix on low speed until fully incorporated.

Whisk together the all-purpose flour, baking soda, salt, cinnamon, and nutmeg in a separate bowl. Gradually mix into the wet ingredients.

Form the dough into a slightly sticky ball, then roll into 1-inch balls and flatten them on the baking sheet.

Bake for 10-12 minutes until golden brown around the edges and just set in the center. Let cool for 5 minutes.

In a saucepan over medium heat, simmer the heavy cream while stirring occasionally.

Blend the brown sugar and cornstarch, whisk into the simmering cream until thickened, about 2-3 minutes.

Spoon the cooled topping onto each cookie.

Broil the cookies on high for 1-2 minutes until the topping caramelizes.

Allow the cookies to cool slightly for the topping to set before serving.