• Line a 9 x 9 x 2-inch pan with parchment paper and lightly spray it with nonstick cooking spray. Set aside.

Crust

• Add 14 squares whole-grain graham crackers, to a food processor and pulse until fine crumbs are formed.
• Add 2 tablespoons melted unsalted butter and 1 tablespoon brown sugar and pulse until combined. This should resemble damp sand.
• Press the crumb mixture evenly into the bottom of the prepared pan. Place it in the refrigerator while you prepare the filling.

Filling

• In a large bowl, beat 1 (8-ounce) package ⅓ less-fat cream cheese, and 1 (14-ounce) can fat-free sweetened condensed milk on high with a hand mixer or a stand mixer fitted with the paddle attachment until smooth and creamy, about 2 minutes. Add 1 teaspoon lemon zest and ½ cup fresh lemon juice and beat until fully incorporated, about 1 minute.
• In a small bowl, combine 2 teaspoons gelatin and 3 tablespoons boiling water and whisk until the gelatin is completely dissolved. Let it cool for 2 to 3 minutes.
• Stir the gelatin into the cream cheese mixture until completely incorporated. Pour the filling over the chilled crust.
• Cover and chill in the refrigerator for at least 6 hours, or overnight, until the filling is completely set. Lift the bars from the pan using the parchment paper and slice into pieces before serving. 8 hours or overnight, until filling is firm.