Preheat oven to 325 degrees F. Generously butter (or use baking spray) on a half sheet pan (approx. 18" x 13"). Set aside.

In a medium bowl, combine flour, baking powder, and salt. Set aside.

In a mixing bowl, of an electric mixer, beat butter and sugar with paddle attachment until light and fluffy, about 3-4 minutes. Add in eggs and almond extract. Beat until combined. Slowly add in flour mixture. Mixing until well blended.

Press this dough into the bottom of your prepared baking dish. Use your fingers or a pastry roller to smooth the top of the dough.

Using a pastry brush, brush the milk to the top of the dough. Sprinkle with sliced almonds, pressing them lightly into the dough.

Bake for 18-20 minutes until done. You don't want to brown these bars.

Cool for about 5 minutes, then cut them with a knife in rectangles. Carefully remove to wire rack and continue to cool.

Once completely cool, then make the glaze by whisking the sugar and almond extract with milk. Drizzle over the bars and allow to set.