Begin by softening 113 g of unsalted butter until it's easy to work with. In a mixing bowl, combine the butter with 200 g of dark brown sugar. Cream the mixture together on medium speed for about 2-3 minutes until it reaches a light and fluffy consistency.

Next, crack 1 large egg into the butter and sugar mix, adding 1 teaspoon of vanilla extract and 1 tablespoon of molasses. Mix these ingredients on low speed until they're fully combined.

In a separate bowl, whisk together 200 g of all-purpose flour, 1 teaspoon of baking soda, 0.5 teaspoon of salt, 0.5 teaspoon of ground cinnamon, and 0.25 teaspoon of ground nutmeg. Gradually sift the dry mixture into the wet ingredients.

Continue mixing until a soft dough begins to form—about 1-2 minutes. Cover with plastic wrap and refrigerate for at least 30 minutes.

While your dough chills, preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

After chilling, remove the dough from the fridge and use a cookie scoop to portion out your dough onto the prepared baking sheet, spacing each scoop about 2 inches apart.

Bake for 9-11 minutes. Watch the edges; they should look set, while the centers remain soft and slightly puffy.

Once baked, allow cookies to cool on the baking sheet for about 5 minutes, then transfer to a wire rack to cool completely.

Once the cookies are completely cool, pipe or spread 1 cup of buttercream frosting on each cookie.

Warm 0.5 cup of toffee sauce until it’s pourable, then drizzle it over each frosted cookie.

Optionally, sprinkle a pinch of flaky sea salt over the warm toffee sauce.