In a large bowl, beat ½ cup granulated sugar, ½ cup packed light or dark brown sugar, ½ cup creamy peanut butter, ½ cup unsalted butter, 1 large egg and 1 tablespoon milk using an electric hand or stand mixer on medium speed until well blended. Stir in 1 ¾ cups oat flour, ¾ teaspoon baking soda, ½ teaspoon baking powder, and ¼ teaspoon fine salt until a smooth dough forms.
Let the dough rest in the fridge for 20 minutes, or up to 24 hours.
When ready to bake the cookies, heat the oven to 375°F and line baking sheets with parchment paper. Shape the dough into 1-inch balls; roll in additional granulated sugar and place them on the baking sheets about 2 inches apart.
Bake the cookies for 8 to 10 minutes or until the edges are a light golden brown. Remove the cookies from the oven and immediately press 1 kiss in the center of each cookie. Then place the cookies on a wire rack to cool and set.
Notes
Make them non-gluten-free - Substitute 1 ½ cups of all-purpose flour for the oat flour and omit the milk if you wish to make these cookies non-gluten-free.
Go dairy-free - Swap the butter for coconut oil or your favorite non-dairy butter and skip the milk or use a plant-based milk.
Try almond butter - If you want a slightly different flavor, swap almond butter for the peanut butter.
Use crunchy peanut butter - I love using smooth peanut butter in these peanut butter blossoms! However, for textural contrast, you can substitute crunchy peanut butter.
Add more salt - These cookies are lightly salted; however, if you like more salt (like me!) you can adjust the amount of salt in the dough for more of a flavor contrast.
Decorate! To make these gluten free peanut butter blossoms even more holiday-festive, decorate them with sprinkles or colored decorating sugar before you pop them in the oven.