Raspberry Sandwich Cookies!

Raspberry Sandwich CookiesThe cookie part of this recipe comes from Martha's Cookie Book.1 1/4 cups all-purpose flour3/4 cup unsweetened Dutch-process cocoa powder1 teaspoon baking soda1/4 teaspoon baking powder1/4 teaspoon salt1 1/2 cups sugar, plus more for flattening cookies10 tablespoons unsalted butter, room temperature1 large egg, room temperaturePreheat the oven to 375 degrees Fahrenheit.