In a small bowl whisk the all-purpose flour, baking powder and salt. Set aside.
In a large bowl beat the softened butter and sugar until creamy. Add the egg and almond extract to the bowl and beat until combined well and creamy.
Add half the flour to the bowl with the butter mixture. Beat until combined. Scrap the bowl with a spatula. Add the remaining flour to the bowl and beat in well.
Divide the dough in half.
Place one piece of dough in the center of a piece of plastic wrap. Fold one piece over the dough and flatten into a disk. Wrap each half of dough tightly and refrigerate for at least two hours or overnight.
Preheat the oven to 375F. degrees. (see notes)
Remove one half of the dough from the refrigerator and roll the linzer dough out on a floured surface with a floured rolling pin. Roll the dough out to ¼ inch thickness.
Cut cookies out with a decorative cookie cutter and transfer to a parchment paper lined baking sheet.
Cut the equivalent number of cookies and cut the centers out with a very small cookie cutter and place on a lined baking sheet. Chill the cookie dough for 20 to 30 minutes before baking.
Bake the cookies 9 to 12 minutes or until the edges are just slightly golden. Remove from the oven and place the hot baking tray on a cooling rack.
Cool for 10 minutes. Transfer the cooled cookies to a cooling rack to cool completely.
Once cooled place a scant teaspoon of raspberry jam on the center of each of the uncut cookie halves.
Place the cookie halves that have the center cut out on top of the cookies with the jam on it. Gently press the cookies together.
Sprinkle the tops of the cookies with powdered sugar if.
Makes about 16 - 2 ½ inch round sandwich cookies.