BASE:

3/4 cup (1 1/2 sticks) unsalted butter, softened
3/4 cup brown sugar packed
1 1/2 cups all-purpose flour
1 cup pecans, chopped
1/8 tsp. salt

Preheat oven to 350°F. Grease a 9x13-inch baking pan.

In a large mixing bowl, beat butter, brown sugar, and salt until light and fluffy. Add flour, 1/2 cup at a time, blending well after each addition. Stir in nuts. Spread evenly over bottom of prepared pan. Bake at 350°F for 12 minutes; remove to a rack.

TOPPING:

2 eggs
2 tsp. instant coffee
1/4 tsp. salt
1/2 cup granulated sugar
1/2 cup brown sugar, packed
1/2 cup Kahlua liqueur
1/3 cup all-purpose flour
1 tsp. baking powder
1 cup coconut flakes
2 tbsp. Kahlua
confectioners' sugar, for dusting

In a small bowl, beat eggs, coffee and salt until light. Beating constantly at medium-high speed, add sugars, 1/4 cup at a time, beating well after each addition. Increase speed to high; continue beating until mixture is thick and pale and ribbons form in bowl when beaters are lifted, 5 to 10 minutes.

With mixer running at medium speed, gradually add 1/2 cup of the liqueur, then flour and baking powder. Beat only until combined. Fold in coconut and pour evenly over partially baked crust.

Bake at 350°F for 20 minutes.

Remove from oven. Drizzle with remaining 2 tablespoons Kahlua and return to oven. Bake until top is set and evenly browned, about 5 minutes. Cool in pan on rack. Dust cooled cookies with confectioners' sugar. Cut into 48 squares (about 1 1/2 inches each).

Store in an airtight container at room temperature for 1 week; freeze for longer storage.

Note: You can leave the Kahlua off the top for non-alcoholic bars.

Makes 48 squares.