Instructions:

• Step 1: Prepare Your Ingredients. Begin by measuring out all your ingredients. This will make the baking process smooth and efficient.
• Step 2: Mix the Dry Ingredients. In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
• Step 3: Cream Butter and Sugar. In a large mixing bowl, use an electric mixer to cream together the room-temperature butter and granulated sugar until light and fluffy, about 3-5 minutes.
• Step 4: Add Eggs. Add the eggs one at a time to the butter-sugar mixture, mixing well after each addition.
• Step 5: Combine Dry and Wet Ingredients. Gradually add the dry ingredient mixture to the wet ingredients, mixing until just combined. Be careful not to over-mix.
• Step 6: Chill the Dough. Cover the dough with plastic wrap and refrigerate for at least 30 minutes. Chilling helps the cookies maintain their shape while baking.
• Step 7: Preheat the Oven. Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
• Step 8: Prepare Cinnamon Sugar. In a small bowl, combine the 2 tablespoons of sugar and 2 teaspoons of cinnamon. This will be used to roll your cookie dough.
• Step 9: Shape the Cookies. Once chilled, scoop out tablespoon-sized portions of dough, roll them into balls, and then roll in the cinnamon sugar mixture. Place them on the prepared baking sheets, spacing them about 2 inches apart.
• Step 10: Bake. Bake in the preheated oven for 10-12 minutes or until the edges are just golden. The centers may look slightly underbaked, but they will firm up as they cool.
• Step 11: Cool the Cookies. Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.
• Step 12: Make the Filling. While the cookies are cooling, prepare the Biscoff cinnamon filling. In a mixing bowl, beat together the softened butter and Biscoff spread until creamy. Gradually add the confectioners' sugar and cinnamon, mixing until combined. Finally, add the milk and mix until smooth.
• Step 13: Assemble the Sandwich Cookies. Once the cookies are completely cool, spread a generous layer of the Biscoff filling on the flat side of one cookie and top it with another cookie, flat side down, to create a sandwich. Repeat with the remaining cookies.