Preheat oven to 350 degrees F (175 degrees C).

Beat butter in a large bowl for 30 seconds until softened.

Add sugar, baking powder, and salt to the butter; beat well until combined.

Incorporate the egg and almond extract into the mixture; beat until thoroughly combined.

Gradually beat in the flour until a dough forms.

Divide the dough into four equal sections.

Place two sections of dough onto a cookie sheet, ensuring they are spaced 4-5 inches apart.

Flatten each dough section into a 3-inch width.

Brush the flattened dough with milk.

Sprinkle the surface generously with coarsely chopped sliced almonds.

Bake in the preheated oven for 12-14 minutes, or until the bars are lightly browned.

While the bars are still warm, cut them diagonally into 1-inch strips.

Transfer the cut bars to a wire rack to cool completely.

Drizzle the cooled bars with almond icing before serving.