To get big lime flavor into our lime bars, we avoided weak, bitter-tasting bottled juice and went with the fresh stuff. But fresh lime juice alone didn’t give us a taste of the Florida Keys; we also added lime zest. We found that regular supermarket, or Persian, limes worked just fine in the filling, and it took only four (as opposed to 20 Key limes) to yield the right amount of juice. For these bars to slice and eat neatly, we needed the filling to be firmer than that of a typical Key lime pie, so we supplemented the usual sweetened condensed milk and egg yolk with cream cheese. Our crust needed to be sturdier, too, and this meant using more crumbs. We had been using graham crackers, but when we increased the amount in the crust their flavor overpowered the filling. Animal crackers had just the right vanilla flavor, and light brown sugar added subtle caramel notes. Key limes can be substituted for the regular limes here, although they have a more delicate flavor; you’ll need about 20 to make ½ cup of juice. Do not substitute bottled Key lime juice. Be sure to zest the limes before juicing them.
Ingredients
- 5 ounces (2½ cups) animal crackers
- 3 tablespoons packed light brown sugar
- Pinch salt
- 4 tablespoons unsalted butter, melted and cooled
- 2 ounces cream cheese, softened
- 1 tablespoon grated lime zest plus ½ cup juice (4 limes)
- Pinch salt
- 1 (14-ounce) can sweetened condensed milk
- 1 large egg yolk
- ¾ cup (2¼ ounces) sweetened shredded coconut, toasted (optional)
- Adjust oven rack to middle position and heat oven to 325 degrees. Make foil sling for 8-inch square baking pan by folding 2 long sheets of aluminum foil so each is 8 inches wide. Lay sheets of foil in pan perpendicular to each other, with extra foil hanging over edges of pan. Push foil into corners and up sides of pan, smoothing foil flush to pan. Grease foil. For the Crust
- Process animal crackers, sugar, and salt in food processor to fine crumbs, about 15 seconds. Add melted butter and pulse to combine, about 10 pulses. Sprinkle mixture into prepared pan and press firmly into even layer. Bake until crust is fragrant and deep golden brown, 18 to 20 minutes, rotating pan halfway through baking. For the Filling
- Stir cream cheese, lime zest, and salt in bowl until combined. Whisk in condensed milk until smooth. Whisk in egg yolk and lime juice until combined.
- Pour filling evenly over crust. Bake until bars are set and edges begin to pull away slightly from sides of pan, 15 to 20 minutes, rotating pan halfway through baking.
- Let bars cool completely in pan on wire rack, about 2 hours, then refrigerate until thoroughly chilled, about 2 hours. Using foil overhang, remove bars from pan. Cut into 16 pieces and top with toasted coconut, if using, before serving. (Uncut bars can be frozen for up to 1 month; let wrapped bars thaw at room temperature for 4 hours before serving.)
