Lightly coat a 9-inch square metal baking pan with cooking spray and line with parchment paper, leaving a 2-inch overhang on all sides. Arrange graham crackers in an even layer in pan, breaking them to fit as necessary.

Place lemon juice in a small bowl and sprinkle with gelatin. Let sit for three minutes until gelatin softens.

In a blender, puree 2 cups of raspberries until smooth, scraping down bowl as needed. Pour through a fine-mesh sieve into a measuring cup, pressing on solids (you should have about 1 cup of puree); discard solids.



In a small saucepan, combine raspberry puree and 1/2 cup sugar over medium heat. Cook until bubbles form at the edges. Add gelatin mixture and cook, stirring constantly until gelatin dissolves (about one minute). Transfer mixture to a small bowl and let cool to room temperature for 20 minutes.

In a large bowl, using an electric mixer, beat cream and 2 tablespoons of sugar at medium-high until firm peaks form (about four minutes). With a rubber spatula, gently fold in raspberry puree mixture until combined. Pour over graham crackers. Smooth top with an offset spatula and arrange 3 cups of raspberries on top.

Refrigerate until set (about 2 hours or as long as overnight).



Using parchment, gently lift pie out of the pan and place it on a serving plate. Peel away parchment from the sides of the pie and trim excess paper with scissors or a sharp knife. Cut into 12 pieces to serve.