Whole Wheat Sugar Cookies

1 cup (2 sticks) unsalted butter, softened
1 cup cane sugar
1 teaspoon vanilla extract
1 large egg
2 teaspoons baking powder
1/2 teaspoon sea salt
3 cups whole wheat pastry flour

Frosting:
1/2 cup (1 stick) butter, softened
4 cups powdered sugar
1 teaspoon vanilla extract

1. Preheat oven to 400°F. Move top rack to top one-third of oven. Line baking sheets with parchment paper or silicone baking mats.
2. Cut butter into chunks. In the bowl of a standing mixer, cream together the butter and sugar. Add egg and vanilla and mix well. 
3. In a separate bowl, combine baking powder, salt, and flour. 
4. Add flour mixture to butter mixture gradually, blending well after each addition.
5. Divide dough in half. On a floured surface, roll each half into a circle 1/8 inch thick. Cut out cookies and place on baking sheets; bake for 6-7 minutes. Reroll the scraps to use up all the dough.
6. Let cookies sit one minute, then transfer to a wire rack to cool completely before frosting.
7. For the frosting, combine the butter, powdered sugar, and vanilla in a bowl until smooth. Use natural food coloring, if desired for some of the frosting. Use a plastic bag with a corner cut off and fill with frosting to pipe decorations onto cookies.