Double-Decker Rhubarb Ice Cream Sandwiches

Ingredients

• 4 tablespoons plus light
• 6 large egg yolk 
• 1 cup raspberries unsweetened frozen with juices thawed
• 5 cups rhubarb fresh unsweetened frozen with juices thawed trimmed
• 1 pinch salt 
• 1.5 cups sugar 
• 1  vanilla pod split
• 0.5 cup whipping cream 

Equipment

• frying pan
• baking sheet
• sauce pan
• whisk
• blender
• ice cream machine

Directions

1. Scrape seeds from vanilla bean into heavy medium saucepan; add bean.
2. Add rhubarb (with juices if using frozen), 1 cup sugar, 2 tablespoons corn syrup and pinch of salt. Cover pan and cook over medium-low heat until rhubarb is tender, about 10 minutes. Cool; discard vanilla bean.
3. Place rhubarb mixture in blender.
4. Add raspberries with juices; purée mixture until smooth.
5. Whisk egg yolks, 1/2 cup whipping cream, remaining 1/2 cup sugar and 2 tablespoons corn syrup in clean heavy medium saucepan to blend well. Stir mixture over medium-low heat until thick enough to coat spoon, about 7 minutes (do not boil).
6. Remove from heat.
7. Mix in 2 1/3 cups rhubarb-raspberry purée. Refrigerate custard until cold. Cover and refrigerate remaining rhubarb-raspberry purée for sauce.
8. Process rhubarb custard in ice cream maker according to manufacturer's instructions. Freeze in covered container.
9. Place 8 Pistachio Meringues on clean baking sheet. Top each meringue with scoop of rhubarb-raspberry ice cream; flatten ice cream to reach edge of meringue. Top each ice-cream-covered meringue with another meringue and another scoop of ice cream; flatten to reach edge. Top each with third meringue. Cover and freeze ice cream sandwiches until firm, about 2 hours. (Can be made 3 days ahead. Keep frozen.)
10. Cut sandwiches in half.
11. Place 2 halves, rounded sides down, on plates.
12. Drizzle with reserved purée.