Prepare the jello by heating 2 cups of water in the microwave for 4-5 minutes until boiling. Stir in the powdered gelatin until dissolved, then add the remaining 2 cups of cold water and stir. Place in the fridge for 30-60 minutes until thickened and syrupy.
1 (6-ounce) box raspberry jello, 4 cups cold water divided
Crush the Nilla Wafers into fine crumbs using a food processor, blender, or by hand with a rolling pin and heavy duty ziploc bag. Set aside 1/2 cup of the crumbs and pat the remaining crumbs into the bottom of a 9x13-inch pan.
1 box finely crushed Nilla Wafers
Whisk 1 and 1/2 cups of the powdered sugar, melted butter, and 1/4 cup of the cream in a medium bowl until thick but drizzly. If the mixture is too thick to drizzle add a little additional cream, one tablespoon at a time. Drizzle this over the Nilla Wafer crumbs. It's okay for some of the crumbs to peek through and there is no need to spread the creamy layer to the edges.
1 3/4 cups powdered sugar divided, 1 Tablespoon salted butter, 1 3/4 cups heavy cream divided
Sprinkle the raspberries evenly over the creamy layer, reserving your best looking raspberries for decorating the top of the dessert when it's done.
18 ounces fresh raspberries
Pour the syrupy, cooled jello over the raspberries, then place in the fridge for 2-3 hours until completely set.
Make the whipped cream by combining the remaining 1 and 1/2 cups of heavy cream with the remaining 1/4 cup of powdered sugar and vanilla extract in a large bowl. Use a stand mixer fitted with a whisk attachment or a hand mixer to beat the cream until stiff peaks form, taking care not to overbeat it. Spread in an even layer on top of the set jello.
2 teaspoons vanilla extract
Sprinkle the reserved Nilla Wafer crumbs over the whipped cream, then decorate with the reserved raspberries. Slice into squares and serve.