Make the base: Stir together graham cracker crumbs, sugar, and melted butter until evenly moistened. Press 2 tbsp firmly into the bottom of each cup using the back of a spoon.
Whip the cream: In a cold bowl, beat heavy cream with a hand mixer or stand mixer until stiff peaks form. Set aside.
Make the filling: In a separate bowl, beat room-temperature cream cheese until completely smooth. Add powdered sugar and vanilla and beat until fluffy. Gently fold in the whipped cream until just combined — don't beat after folding.
Fill: Spoon or pipe the filling into each cup over the graham cracker base, filling to just below the rim.
Chill: Cover and refrigerate for at least 2 hours or overnight.
Serve: Top each cup with sliced strawberries and blueberries within 2 hours of serving. Serve cold.