- Preheat the oven to 350°F and line a muffin tin with paper liners. 
- In a large bowl, whisk together cake mix, water, oil, egg whites, lemon zest, and lemon juice until smooth. 
- Gently fold in the raspberries with a spatula so they stay mostly whole. 
- Divide the batter evenly among the cupcake liners, about 2/3 full. 
- Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean. 
- Let them cool completely on a wire rack. 
- Top each cupcake with a generous dollop of whipped topping. 
- Garnish with extra lemon zest and a raspberry or two. Serve chilled or at room temp.