In a large mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until well combined.
In a separate bowl, cream the softened unsalted butter with the granulated sugar and powdered sugar until light and fluffy, about 3 minutes.
Gradually add the dry ingredients to the butter and sugar mixture, mixing on low speed until fully incorporated and a crumbly dough forms.
Transfer the cookie mix to an airtight container or a large resealable plastic bag.
Label the container with the date and store in a cool, dry place until ready to use.
To make sugar cookies from the mix: Preheat oven to 350°F (175°C). In a mixing bowl, combine 1 cup of sugar cookie mix with 1 large egg and 1 teaspoon vanilla extract. Mix until a dough forms.
Roll dough into 1-inch balls and place them 2 inches apart on an ungreased baking sheet. Flatten slightly with the bottom of a glass or your palm.
Bake for 8-10 minutes or until edges are lightly golden. Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.