Preheat oven to 375 degrees. Line a heavy baking sheet with parchment paper or a silpat.
In a medium saucepan, combine butter, water, 1 1/2 tsp sugar and salt over high heat until mixture boils and butter melts.
Reduce heat to medium and add flour, stirring for 1 minute. Remove from heat and allow to cool 5 minutes.
Crack two eggs in a small bowl. One at a time, beat into the dough with a wooden spoon. Place large spoonfuls onto prepared baking sheet- you should get about 10-12 mounds.
Beat the remaining egg and use a pastry brush to gently coat the mounds with egg wash. Bake until amber brown in color, about 50 minutes. Remove and allow to cool completely.
While they cook, combine the mascarpone, ricotta, vanilla and remaining sugar and mix until light and fluffy. Refrigerate and chill until cold.
Combine the Nutella and whipping cream and microwave for 30 seconds. Stir until combined and warm.
Recipe Notes
When ready to serve, cut the profiteroles in half with a serrated knife. Put a dollop of mascarpone cream inside, and drizzle the Nutella sauce over the top. Serve with whipped cream, if you desire.
Suggested Wine Pairing
Serve with a glass of Bogle Petite Sirah Port or Blanc de Blancs.