Preheat oven to 350 degrees. Line a 12-cup muffin tin with paper liners and spray with cooking spray.
For the Cupcakes: Combine dry cake mix, dry pudding mix, water, oil, Greek yogurt, eggs and vanilla. Mix until well blended. Fill muffin cups no more than 2/3 full with batter.
Bake for about 23 minutes or until top springs back when lightly touched and a toothpick inserted in the center comes out clean. Repeat with remaining batter. Cool completely and then spread 1 - 1 1/2 teaspoons of Nutella over the top of each cupcake. Top with Strawberry Whipped Cream. Store cupcakes in the refrigerator. Yield: 24-26 cupcakes.
For the Strawberry Whipped Cream:
Pour whipping cream into a chilled bowl. Using a hand mixer and the whisk attachment, beat the cream until frothy. Add the strawberry jam, sugar and strawberry extract. Whip until thick and creamy. Pipe or spread over cupcakes. Garnish with a sliced strawberry, if desired.