Instructions

1. Adjust the oven rack to middle position and heat oven to 325 F. Line an 8 x 8 baking pan with 2 pieces of foil perpendicular to each other, leaving overhang on all 4 sides. Spray foil with nonstick cooking spray.

For the crust:

1. Pulse animal crackers in the food processor until broken down, ~ 10 pulses. Process the crumbs until evenly fine, about 10 seconds (you should have about 1 1/4 cups crumbs). Add brown sugar and salt; process to combine, 10 – 12 pulses (if large sugar lumps remain, break them apart with fingers). Drizzle butter over crumbs and pulse until crumbs are evenly moistened, ~ 10 pulses. Press crumbs evenly and firmly into bottom of prepared pan. Bake until deep golden brown, 18 to 20 minutes. Cool on wire rack while making filling. Do not turn off oven.

For the filling:

1. While crust cools, in medium bowl, stir cream cheese, zests, and salt with rubber spatula until softened, creamy, and thoroughly combined. Add the condensed milk and whisk vigorously until incorporated and no lumps of cream cheese remain. Whisk in the egg yolk. Add the 3 juices and whisk gently until incorporated (mixture will thicken slightly).
2. Pour filling into crust; spread to the corners and smooth the surface with rubber spatula. Bake until set and edges begin to pull away slightly from sides, 15 to 20 minutes. Cool on wire rack to room temperature, 1 to 1 1/2 hours. Cover with foil and refrigerate until thoroughly chilled, at least 2 hours.
3. To serve, loosen edges with paring knife and lift bars from baking pan using foil extensions. Cut the bars into 16 squares. Leftovers can be refrigerated up to 2 days; the crust will soften slightly. Let the bars stand at room temperature about 15 minutes before serving.