Preheat oven to 350°F.
Line baking sheets with foil; butter and flour foil.
Melt 1/2 cup butter in medium skillet over medium heat.
Add sugar, 1 tablespoon flour and salt and stir until sugar dissolves, about 3 minutes.
Mix in almonds and milk and stir until slightly thickened.
Remove from heat and blend in almond extract.
Let cool slightly.
Drop batter onto prepared baking sheets by teaspoons, spacing 3 1/2 to 4 inches apart.
Bake cookies, 1 sheet at a time, until light golden brown, about 5 to 7 minutes.
Let stand about 2 minutes to firm slightly, then remove cookies from foil and transfer to rack to cool.
Using thin metal spatula, spread layer of chocolate on bottom side of half of cookies.
Cover with flat side of plain cookie to form sandwich.
Cool on rack until chocolate is set.