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

In a medium bowl, whisk together 2 ½ cups of all-purpose flour, 1 tsp of baking soda, ½ tsp of baking powder, and ½ tsp of salt.

Melt ¼ cup of butterscotch chips in a microwave-safe bowl until smooth.

Combine ¾ cup of softened unsalted butter, ½ cup of granulated sugar, and ¾ cup of packed light brown sugar in a large mixing bowl and cream these ingredients until fluffy and light.

Add the melted butterscotch chips, 2 large eggs, 2 tsp of vanilla extract, 1 tsp of butter extract, ¼ tsp of optional rum extract, and 2 tbsp of cream soda to the butter and sugar mixture.

Gradually combine your dry flour mixture into the wet batter on low speed.

Cover your mixing bowl with plastic wrap and place it in the refrigerator for 30 minutes to 2 hours.

Form the chilled dough into balls and place on prepared baking sheets spaced about 2 inches apart. Bake for 10-12 minutes.

Cool the cookies on the baking sheets for about 5 minutes, then transfer to a wire rack.

Prepare the butterscotch buttercream frosting by beating ½ cup of softened unsalted butter, 3-4 cups of powdered sugar, ¼ cup of melted butterscotch chips, 1 tsp of vanilla extract, and ½ tsp of butter extract together. Adjust consistency with 2-3 tbsp of heavy cream or milk.

Frost cookies once fully cooled, and drizzle with butterscotch sauce if desired.