In a medium bowl, cream together the butter and sugar until light and fluffy. Add the egg and vanilla and beat until smooth. Sift together the flour and salt and slowly stir into butter mixture until just blended.
Divide batter in half and place each half on in the center of two ungreased, flat-sided cookie sheets. Dip a spatula in warm water and spread batter to cover the entire baking sheet, making sure batter is spread evenly. Sprinkle almonds and press gently into dough.
Bake each sheet about 12 minutes, or until edges are lightly browned. Cut hot cookies into 2-inch squares. Return to oven and bake until lightly golden... about 5 minutes. Watch carefully to prevent over baking.
Remove from oven to a wire rack. Slide spatula under cookies to loosen. Cool completely on cookie sheets. Store in airtight containers with waxed paper between layers.