In a medium bowl, whisk together flour, baking powder, and salt; set aside.

In the bowl of a stand mixer, beat butter and sugars until light and fluffy, about 3 minutes. Add the egg and maple extract; beat until combined. Add the dry ingredients and beat until just combined.

Divide dough into two balls and flatten each into a disk. Wrap in plastic wrap and refrigerate for at least one hour.

Preheat oven to 375 degrees F. Line baking sheets with parchment paper.

Remove dough from refrigerator and roll out to about 1/4-inch thickness.

Use a cookie cutter to cut out cookies and place them on prepared baking sheets.

Bake cookies for 8-10 minutes or until edges just start to brown.

Cool cookies on baking sheets for about 3 minutes, then transfer to a wire rack to cool completely.

Make the filling by creaming butter, then adding confectioners sugar and maple syrup until smooth.

Spread filling onto the backside of one cookie and top with another cookie.