Peanut Brittle Ice Cream Sundaes with Chocolate Sauce

PreparationFor Peanut Brittle: Lightly butter large baking sheet. Combine sugar, corn syrup and water in heavy medium saucepan. Stir over medium-low heat until sugar dissolves. Attach clip-on candy thermometer to side of pan. Increase heat to medium. Using wooden spoon, stir constantly but slowly until temperature reaches 300°F, occasionally brushing down sides of pan with wet pastry brush, about 20 minutes. Remove from heat; immediately add baking soda and stir until very foamy. Immediately stir in peanuts. Working quickly, pour out onto baking sheet. Cool completely. Coarsely chop peanut brittle. (Can be made 3 days ahead. Store in airtight container.) For Ice Cream: Combine milk and sugar in heavy medium saucepan. Scrape in seeds from vanilla bean; add bean. Stir over medium heat until sugar dissolves. Bring to boil. Remove from heat. Whisk yolks in medium bowl to blend. Gradually whisk in hot milk mixture. Return mixture to saucepan. Stir over medium-low heat until custard thickens and leaves path on back of spoon when finger is drawn across, about 2 minutes (do not boil). Strain into bowl. Whisk in cream. Chill. Process custard in ice cream maker according to manufacturer's instructions. Transfer to large container. Mix in 2 cups chopped peanut brittle. Cover and freeze. Reserve remaining brittle for garnish. (Can be made 3 days ahead. Keep frozen.) For Chocolate Sauce: Bring water and corn syrup to simmer in heavy medium saucepan. Reduce heat to low. Add both chocolates and stir until smooth. (Can be made 1 day ahead. Cover; chill. Rewarm over low heat.) Serve warm. Top ice cream with Chocolate Sauce, whipped cream and peanut brittle.

PreparationFor Peanut Brittle: Lightly butter large baking sheet. Combine sugar, corn syrup and water in heavy medium saucepan. Stir over medium-low heat until sugar dissolves. Attach clip-on candy thermometer to side of pan. Increase heat to medium. Using wooden spoon, stir constantly but slowly until temperature reaches 300°F, occasionally brushing down sides of pan with wet pastry brush, about 20 minutes. Remove from heat; immediately add baking soda and stir until very foamy. Immediately stir in peanuts. Working quickly, pour out onto baking sheet. Cool completely. Coarsely chop peanut brittle. (Can be made 3 days ahead. Store in airtight container.) For Ice Cream: Combine milk and sugar in heavy medium saucepan. Scrape in seeds from vanilla bean; add bean. Stir over medium heat until sugar dissolves. Bring to boil. Remove from heat. Whisk yolks in medium bowl to blend. Gradually whisk in hot milk mixture. Return mixture to saucepan. Stir over medium-low heat until custard thickens and leaves path on back of spoon when finger is drawn across, about 2 minutes (do not boil). Strain into bowl. Whisk in cream. Chill. Process custard in ice cream maker according to manufacturer's instructions. Transfer to large container. Mix in 2 cups chopped peanut brittle. Cover and freeze. Reserve remaining brittle for garnish. (Can be made 3 days ahead. Keep frozen.) For Chocolate Sauce: Bring water and corn syrup to simmer in heavy medium saucepan. Reduce heat to low. Add both chocolates and stir until smooth. (Can be made 1 day ahead. Cover; chill. Rewarm over low heat.) Serve warm. Top ice cream with Chocolate Sauce, whipped cream and peanut brittle.