1. Prepare the Berries: Start by gently washing all your fresh berries. Hull and slice the strawberries into bite-sized pieces. Leave the blueberries and raspberries whole. Set them aside in separate bowls. This initial prep makes assembly much smoother.

2. Create the Creamy Layer: In a medium bowl, combine the thawed whipped topping, Greek yogurt, granulated sugar (if using), and vanilla extract. Gently fold everything together until it’s well combined and smooth. Be careful not to overmix, as this can deflate the whipped topping. This mixture will form the “white” layer of your parfaits.

3. Start the Layers: Red: Take your first dessert cup. Place a spoonful of sliced strawberries at the very bottom, creating a vibrant red base. Make sure to spread them out evenly so they cover the bottom of the cup.

4. Add the White Layer: Carefully spoon a layer of the creamy whipped topping and yogurt mixture over the strawberries. Use the back of the spoon to gently spread it to the edges of the cup, creating a distinct white layer.

5. Introduce the Blue Layer: Next, add a layer of fresh blueberries on top of the creamy white mixture. Arrange them neatly so they are visible through the clear cup, forming your blue stripe.

6. Repeat the Layers: Continue layering, starting with more strawberries, then the creamy white mixture, and finally more blueberries. Repeat this sequence until your dessert cups are full, ending with a colorful top layer of mixed berries for a beautiful presentation.

7. Final Touches: Once all your parfaits are assembled, you can serve them immediately or chill them in the refrigerator for a short period. A final garnish of a whole strawberry or a few extra blueberries on top can make them look even more appealing.