1. Preheat oven to 375. Line a baking sheet with parchment paper.
2. In a medium saucepan, combine water, butter, and salt. Bring to a rolling boil over medium-high heat. Beat in flour, stirring constantly, until mixture forms a ball. Remove pan from heat, and let cool for 5 minutes.
3. Beat in eggs, one at a time, at medium speed with an electric mixer until mixture is smooth.
4. Spoon or pipe dough into 10 (2-inch) mounds onto prepared baking sheet. Bake for 30 to 33 minutes or until puffed and golden brown. Set aside to cool.
5. Cut cream puffs in half horizontally. Remove soft dough from inside. Spoon Nutella into bottoms of cream puffs and sprinkle with hazelnuts. Cover with tops of cream puffs. Garnish with whipped cream, chocolate and Strawberries, if desired.