1 cup apricot preserves
3 tablespoons orange liqueur (such as Grand Marnier)
1 cup (2 sticks) unsalted butter, room temperature
3/4 cup sugar
1 teaspoon almond extract
2 cups all purpose flour
1/4 teaspoon salt
2 oz (1/4 cup) almond paste, crumbled
1/2 cup sliced almonds, divided
Preheat oven to 325°F.
Butter a 9 by 9 by 2-inch metal baking pan; line bottom and sides of pan with parchment paper, extending over sides. Butter parchment. Mix preserves and orange liqueur in small bowl; set aside.
Using electric mixer, beat 1 cup butter and sugar in large bowl until well blended. Beat in almond extract. Add flour and salt; beat just until blended. Transfer 1 cup of dough to another small bowl; add crumbled almond paste and mix with fingertips until small clumps form. Mix in 1/4 cup sliced almonds; set aside for topping.
Press remaining dough evenly onto bottom of prepared pan. Spread preserves mixture evenly over. Using fingertips, coarsely crumble topping over preserves, then sprinkle 1/4 cup almonds over. Press topping lightly into preserves.
Bake shortbread until top and crust edges are golden brown, about 1 hour. Cool completely in pan on rack. Using parchment paper as aid, lift shortbread from pan. Cut shortbread into 4 equal strips, then cut each strip crosswise into 8 small bar cookies.