Serves 4
3-4 stalks (1 lb) rhubarb, trimmed and thinly sliced
6 Tbsp dark brown sugar
4 cups vanilla ice cream, softened
10 Tbsp sugar, divided
1/8 to1/4 tsp cinnamon (I increased the cinnamon to our taste.)
1/2 cup softened, unsalted butter
1 tsp vanilla extract
1/8 tsp kosher salt
1 cup plus 2 Tbsp flour
2 cups (12 oz) blueberries
1/2 tsp cornstarch
1 Tbsp lemon juice
Cook rhubarb with brown sugar in a medium frying pan over medium-low heat until it looks like jam, 20 minutes. Put in a bowl and chill. Stir in ice cream and freeze until firm, 3 hours.
Preheat oven to 350° F. Line a baking sheet with parchment paper. Mix 1 Tbsp sugar and the cinnamon in a bowl. Beat butter, 5 Tbsp sugar, the vanilla, and salt in a bowl until light and fluffy. Add flour and mix on low until large clumps form.
Gather dough into a ball and roll into a 1/4-inch thick round. Transfer to a baking sheet, sprinkle with cinnamon sugar, and freeze until firm, 10 minutes. Bake until edges are golden brown, 15 to 20 minutes. Cool, then break into large shards.
Put berries, cornstarch, lemon juice, and remaining sugar in a small saucepan. Bring to a simmer over medium-low heat and cook, stirring, until thick and bubbly, 5 minutes.
Divide berry compote among 4 bowls. Scoop ice cream into each bowl and add crust shards.