-
1
Put oven rack in middle position and preheat oven to 350u00b0F.
-
2
Whisk together flour, sugar, baking powder, and 1/4 teaspoon salt in a large bowl, then blend in butter with your fingertips or a pastry blender until mixture resembles coarse meal.
-
3
Add 1 whole egg and 2 yolks to flour mixture, reserving whites, then knead in bowl until a soft dough forms, about 5 minutes. Put 3/4 cup dough between 2 large sheets of plastic wrap and roll out into a 9 1/2-inch round, then chill 15 minutes.
-
4
Transfer remaining dough to springform pan and cover surface with another large sheet of plastic wrap. Press dough (through plastic wrap) evenly onto bottom. Discard plastic wrap.
-
5
Blend almond paste, cinnamon, and 1 tablespoon water in a food processor until crumbled (paste may be hard). Add remaining 3 tablespoons water, a little at a time, processing until paste is smooth.
-
6
Beat together reserved whites and remaining 1/8 teaspoon salt in a medium bowl with an electric mixer at medium-high speed until they just hold stiff peaks, then fold in almond paste mixture gently but thoroughly.
-
7
Spread almond mixture on top of dough in pan, tapping side of pan gently to smooth surface.
-
8
Remove top sheet of plastic from remaining dough and cut dough into 1/2-inch-wide strips, then arrange 6 strips 1 inch apart diagonally across almond mixture. Trim ends of strips flush with edge of pan. Arrange 6 of the remaining strips 1 inch apart diagonally across first strips to form a lattice with diamond-shaped spaces. (If dough becomes too soft, chill until firm.) Repair any broken strips of dough by carefully pressing them together and trim ends of strips flush with edge of pan. Discard any remaining strips.
-
9
Bake until pale golden, about 45 minutes. Cool in pan on a rack 10 minutes. Run a thin knife around edge of cake to loosen if necessary, then remove side of pan and cool cake completely, about 30 minutes.
