Mix together the topping: oats, sugar, flour, cinnamon, and butter, until crumbly. Bake at 350 F for 10-15 minutes or until golden brown. Remove from oven & cool.
Prepare your fresh whipped cream by whipping the cream, powdered sugar, and vanilla together until stiff peaks form.
Layer parfait with strawberries, fresh whipped cream, blueberries, and top with crisp topping. Serve immediately.
Tips for the perfect whipped cream:
If you can, start with cold everything: cream, bowl, and beaters. Keep the cream refrigerated until ready to use. I measured mine out and placed the measuring cup in the freezer (but watch closely, it freezes fast). I also put my Bosch mixing bowl and beaters in the freezer for at least 10 minutes before I was going to use it to whip the cream. The colder the better. The whipped cream should come together in approx. 3 minutes. Don't whip too long, otherwise you'll make butter!
Adapted from Tried and Tasty Apple Crisp