For the crust: Process the graham crackers and brown sugar in a food processor until finely ground, about 1 minute. With the processor running, slowly pour in the melted butter. Process the mixture until it is the texture of coarse sand.

Spray a 9-by-9-inch square baking dish with cooking spray. Transfer the graham cracker mixture to the dish and press the mixture into the bottom, using the flat bottom of a measuring cup to make an even layer (press firmly). Freeze for at least 20 minutes and up to 2 days.

For the filling: In the bowl of a stand mixer fitted with the whisk attachment, beat the heavy cream on medium-high speed until stiff peaks form, about 3 minutes. Transfer the mixture to a large bowl.

Combine the cream cheese, powdered sugar, and vanilla in the same bowl used to beat the heavy cream (no need to wipe it clean). Beat on medium-high speed until light, fluffy, and smooth, about 3 minutes. Remove from the mixer and whisk in a third of the whipped cream by hand, then gently fold in the rest using a rubber spatula. Spread half of the cream cheese mixture over the graham cracker crust in an even layer.

In a medium bowl, stir together the strawberry gelatin and ½ cup boiling water until dissolved, about 2 minutes.

Beat ⅓ cup of the strawberry gelatin into the remaining cream cheese mixture until fully incorporated. Spread over the top of the plain cream cheese layer.

Toss the sliced strawberries in the remaining strawberry gelatin to fully coat. Spoon the strawberries over the cream cheese in an even layer. Chill until set, at least 4 hours and up to 12 hours. (If chilling longer than 4 hours, cover with plastic.)