Step 1
In a heavy saucepan, combine water, butter and salt; bring to full boil. Remove from heat. Add flour all at once, stirring vigorously with wooden spoon until mixture forms smooth ball that leaves side of pan. Return to medium-low heat; cook, stirring constantly, for 2 minutes. Let cool for 5 minutes.
Step 2
Using an electric mixer beat in eggs, one at a time, beating well after each addition; continue beating until dough is smooth and shiny.
Step 3
With spoon or pastry bag fitted with straight tip, drop a 2 inch (5 cm) mound of dough for each profiterole, about 2 inches (5 cm) apart onto parchment paper-lined or lightly greased baking sheet. Bake in 400 F (200 C) oven for about 25 minutes or until puffed, golden and crisp. Let cool completely. Cut each in half.
Step 4
Chocolate Mousse: Place chocolate in a heatproof bowl. In a saucepan, bring 1/2 cup (125 mL) of the cream just to the boil. Pour over chocolate and add vanilla; whisk until smooth. Let cool to room temperature, stirring occasionally for about 30 minutes or until slightly thickened.
Step 5
In a large bowl, beat remaining cream with sugar until stiff peaks form. Fold half into the chocolate mixture. Fold in remaining whipped cream until well combined. Scrape into a piping bag and fill each profiterole with mousse. Drizzle with Chocolate Drizzle.
Step 6
Chocolate Ice Cream Variation: Fill each profiterole with scoop of chocolate ice cream. Replace tops. Freeze on baking sheet until solid and place in airtight container for up to 1 month. Let thaw slightly before serving. Drizzle with chocolate drizzle to serve.
Step 7
Chocolate Drizzle: In a small saucepan bring 1/4 cup (60 mL) of 35% whipping cream to a simmer. Remove from heat and whisk in 2 oz (60 g) chopped bittersweet chocolate until smooth.