01 - In a large mixing bowl, whisk together sweetened condensed milk, Greek yogurt, key lime juice, lime zest, vanilla extract, and salt until thoroughly blended.
02 - In a separate chilled bowl, whip heavy cream with an electric mixer or whisk until stiff peaks form.
03 - Gently fold the whipped cream into the lime mixture until smooth and fully combined.
04 - Line a 9x9-inch pan with parchment paper. Pour the ice cream mixture into the pan and smooth the surface evenly. Freeze for at least 4 hours or until set.
05 - Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.
06 - In a mixing bowl, combine graham cracker crumbs, all-purpose flour, baking powder, and salt.
07 - In another large bowl, beat together unsalted butter and brown sugar until light and fluffy. Beat in egg and vanilla extract until well mixed.
08 - Gradually stir the dry mixture into the creamed butter mixture until a dough forms. Avoid over-mixing.
09 - Scoop 16 tablespoon-sized portions of dough onto the prepared baking sheet, flattening each slightly. Bake for 8–10 minutes or until golden. Allow cookies to cool completely on a wire rack.
10 - Once the ice cream is solid, use a round cookie cutter matching the cookies’ size to cut out discs from the frozen mixture.
11 - Place each ice cream disc between two graham cracker cookies to form sandwiches. Serve immediately, or wrap and store in the freezer until ready to serve.