Maple Sandwich Cookies are made without any eggs. For a non-dairy version, substitute Nutiva shortening for the butter. For the maple flavoring, I used Watkins.
Mix together the flour, baking powder and salt and set aside.
In a mixing bowl, using a handheld electric mixer, beat the butter and sugar until light and fluffy. Beat in the maple syrup and maple flavoring until combined.
Add the flour and stir until you have a thick dough.
Preheat the oven to 375ºF. Line two baking sheets with parchment paper.
At this point you can roll the dough a little over ⅛ inch thick on a floured surface and cut circles the traditional way or you can use the method I like. Scoop up rounded teaspoonfuls of dough and arrange them 2 ½ inches apart on parchment lined baking sheets. Press them down flat so that they are ⅛ inch "not-so-perfect" circles -- make sure they are a little over 2 inches in diameter. Now take a 2 inch round cutter and press it into your imperfect circle. Trim so that you have a perfect circle. Repeat with each round of dough.
Bake one sheet at a time for 8 to 10 minutes, or just until the cookies start to brown around the edges. Let cool on the sheets for a few minutes, then transfer to a wire rack to cool completely.
Make the filling: Beat the butter with a handheld electric mixer until creamy.
Add the confectioners’ sugar, maple syrup, and salt and beat until smooth.
Spread the underside of half of the cookies with the filling, then cap with remaining cookies.
Notes
The yield will vary depending on how thick your roll or cut your dough and whether or not your cookie cutter is really 2 inches. You'll get a few more cookies if you use a cutter that is 1 ¾ inches.