Ingredients

• 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)

Instructions

1. 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.
2. 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.
3. 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.
4. 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.
5. *Available at Sweet Celebrations (800-328-6722).