In a medium bowl, cream butter and sugar.
Add eggs and almond extract; mix until fluffy.
Stir in flour, baking powder and salt; mix well.
Divide dough into four pieces, and roll each one into a log about twelve inches long.
Place two logs per cookie sheet with room to expand between them.
Flatten each roll by hand until it is about three inches wide.
Brush flattened roll with milk and sprinkle with sliced almonds.
Bake in preheated oven 12 to 15 minutes or until edges are slightly browned.
While the cookies are still warm, cut them crosswise at a diagonal, into slices about 1 inch wide.
In a small bowl, stir together powdered sugar, almond extract, and milk until smooth.
Drizzle the icing over the cookies once they have cooled.