I made a key lime cheesecake a few months ago, but it was a little too tart for my husband. He gave these bars a thumbs up, and I do too. The lime flavor is definitely present but is tempered by all the sweetness from the sweetened condensed milk and the crust. These are quite refreshing!
Key Lime Bars
adapted from Cook's Illustrated via Tracey
5 ounces graham crackers
3 tablespoons packed brown sugar (light or dark)
pinch table salt
4 tablespoons unsalted butter, melted and cooled slightly
2 ounces cream cheese, room temperature
1 tablespoon grated lime zest
pinch table salt
1 (14-ounce) can sweetened condensed milk
1 egg yolk
1/2 cup fresh key lime juice (regular lime juice works too in a pinch)
Preheat oven to 325 F. Fit a large piece of heavy-duty aluminum foil into the bottom and up the sides of an 8-inch square baking dish, letting the ends hang over so you can use them to lift the bars out after they've baked. Spray the foil with nonstick cooking spray.
In the bowl of a food processor, pulse the graham crackers until they are broken down into fine crumbs (you should have about 1 1/4 cups of crumbs). Add the brown sugar and salt and process to combine, about ten 1-second pulses. Drizzle the butter over the crumb mixture and pulse until the crumbs are evenly moistened with butter, about ten 1-second pulses. Dump the mixture into the prepared baking pan and use your fingers to press the crumbs evenly to form the crust in the bottom of the pan. Bake until golden brown, about 15 minutes. Remove the pan from the oven and set on a wire rack to cool while you make the filling.
In a medium bowl, use a rubber spatula to stir the cream cheese, lime zest and salt until softened and thoroughly combined. Add the sweetened condensed milk and whisk until fully incorporated - no lumps of cream cheese should remain. Whisk in the egg yolk. Finally, add the lime juice and whisk gently until it is incorporated. Your filling mixture will thicken slightly.
Pour the filling on top of the crust, spread it into the corners and smooth the surface with a rubber spatula. Bake until the filling is set and the edges begin to pull away slightly from the sides of the pan, about 15 to 20 minutes. Cool on wire rack to room temperature, 1 to 1 1/2 hours. Cover the pan with foil and refrigerate until thoroughly chilled, at least 2 hours. Use the foil "handles" to lift the bars out of the pan then cut them into squares before serving. Store the bars in the refrigerator.