Preheat oven to 350 F
Line a baking sheet with parchment paper or baking mat
In a large bowl, beat together butter, sugar, and brown sugar until well blended (using a stand mixer works best)
Combine the baking soda and 1 tbsp hot water in a small bowl. Stir until the baking soda is dissolved
Add the baking soda mix into the butter and sugar mixture. Add the vanilla and (optional) almond extract. Continue to mix until well blended
In a separate large bowl, whisk together the flour, baking powder, cornstarch, and salt until well blended
Gradually add the flour mixture to the butter and sugar mixture
Add the milk 1 tbsp at a time until the dough comes together. Form into a silky smooth ball
Place the dough on a lightly floured surface, using additional flour as needed to avoid sticking. Lightly flour the top of the dough
Roll out the dough to ¼-inch thickness. Use parchment paper between the rolling pin and dough to prevent sticking
Using your favorite Halloween cookie-cutters, cut out the cookies
Place cookies 1 inch apart on the lined baking sheet
Bake for 10 - 15 minutes
Allow cookies to completely cool on a wire rack before adding frosting
