Almond Bar Cookies
1/2 cup packed canned almond paste* (about 5 oz; not marzipan), coarsely crumbled
1/2 teaspoon salt
3/4 cup sugar
2 sticks (1 cup) unsalted butter, softened
1 large egg, separated
1 teaspoon almond extract
1 1/4 cups all-purpose flour
1/2 cup sliced almonds (about 1 1/2 oz)
Pulse almond paste in a food processor until broken up into small bits, then add salt and 1/4 cup sugar and continue to pulse until finely ground, about 1 minute.
Put oven rack in middle position and preheat oven to 350°F. Butter a 9-inch square baking pan, then line with foil, leaving a 2-inch overhang on 2 opposite sides, and butter foil.
Beat together butter and remaining 1/2 cup sugar in a large bowl with an electric mixer at medium-high speed until pale and fluffy, about 3 minutes in a stand mixer (preferably fitted with a paddle attachment) or 6 minutes with a handheld. Add almond mixture, egg yolk, and almond extract and beat until combined well, about 2 minutes. Reduce speed to low, then add flour and mix until combined. Spread batter evenly in pan with an offset spatula. Lightly beat egg white in a small bowl, then brush some of it over batter and sprinkle evenly with almonds.
Bake until top is golden, 35 to 40 minutes. Cool completely in pan on a rack, about 1 hour. Transfer with foil to a cutting board, then discard foil. Cut into squares or rounds.
*Available at Sweet Celebrations (800-328-6722).