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

Cream together softened butter, granulated sugar, and brown sugar until smooth and creamy, about 3-5 minutes.

Add in the egg and vanilla extract, mixing until fully combined and light and fluffy.

In another bowl, whisk together flour, baking powder, and salt. Gradually add to wet ingredients and mix gently.

Portion out 7-8 equal-sized balls of dough onto the prepared baking sheet and flatten each to about ¾ inch thick.

Bake for 12-13 minutes until the edges are lightly golden while the centers appear slightly underbaked.

Allow cookies to cool on the baking sheet for about 10 minutes before transferring to a wire rack.

Cream the softened butter for frosting until smooth, then gradually mix in powdered sugar, vanilla extract, and heavy cream until fluffy.

Add in the butterscotch syrup, mixing until beautifully blended.

Once cookies have cooled, pipe or spread the frosting generously on each cookie and top with sprinkles.