•Squares keep, covered and chilled, 3 days. Bring to room temperature before serving
Recipe information
Total Time
2 hr
Yield
Makes 12 squares
Ingredients
For shortbread base
For apple filling
Preparation
Step 1
Preheat oven to 350°F.
Prepare bread crumbs:
Step 2
Grind bread to fine crumbs in a food processor. Spread in a shallow baking pan and toast in middle of oven, stirring once, until golden, about 5 minutes. Leave oven on.
Make shortbread base:
Step 3
Cut butter into 1/2-inch pieces, then pulse in a food processor with flour, brown sugar, and salt until it begins to form small lumps. Sprinkle base into a 13- by 9-inch baking pan and press evenly onto bottom. Bake in middle of oven until golden, about 20 minutes.
Prepare filling while shortbread is baking:
Step 4
Melt butter and keep warm. Peel, quarter, and core apples and thinly slice quarters crosswise. Stir together sugar and flour in a small bowl.
Assemble and bake squares:
Step 5
Sprinkle half of sugar mixture over hot shortbread, then top with apples and sprinkle with remaining sugar mixture. Top with bread crumbs and drizzle all of butter over them.
Step 6
Bake in upper third of oven, pressing down on filling with a metal spatula halfway through baking, until apples are very tender and bread crumbs are golden, 50 minutes to 1 hour total. Cool 20 minutes in pan on a rack.