|Rhubarb||2 Pound, trimmed and cut into 1 inch pieces to make about 8 cups|
|Granulated sugar||3 Cup (48 tbs)|
|Ginger ale||1⁄2 Cup (8 tbs)|
|Cornstarch||1⁄2 Cup (8 tbs)|
|Minced ginger||1 Tablespoon, or grated|
|Packed brown sugar||1 Cup (16 tbs)|
|Rolled oats||1 Cup (16 tbs)|
|Butter||1⁄2 Cup (8 tbs), softened|
|All purpose flour||1⁄2 Cup (8 tbs)|
|Ground cinnamon||1 Teaspoon|
|Ground cardamom||1 Teaspoon|
|Ground cloves||1⁄2 Teaspoon|
|For buttermilk ice cream|
|Whipping cream||2 Cup (32 tbs)|
|Buttermilk||2 Cup (32 tbs)|
|Sugar||2 Cup (32 tbs)|
|Vanilla bean/2 teaspoons vanilla extract||1|
FOR THE ICE CREAM, combine 1 cup of the whipping cream and the egg yolks in the top of a double boiler and set it over a pan of lightly simmering (not boiling) water.
Gently heat the mixture, stirring constantly, until thickened and creamy.
Remove from the heat.
In another bowl, combine the remaining 1 cup whipping cream with the buttermilk and sugar.
Split the vanilla bean and scrape its seeds into the bowl, discarding the rest of the vanilla bean, or add the vanilla extract.
Stir in the hot mixture.
Pour the mixture into an ice cream maker and freeze according to the manufacturer's instructions.
Transfer to an airtight container and freeze until set.
PREHEAT THE OVEN to 350°F Lightly grease a 9- by 13-inch baking dish.
TOSS TOGETHER THE RHUBARB, sugar (to taste), ginger ale, cornstarch, and gingei in a large bowl until the ingredients are well mixed and the cornstarch has dissolved.
Spread evenly in the baking dish.
COMBINE THE BROWN SUGAR, oats, butter, flour, cinnamon, cardamom, and cloves in another bowl.
Stir until thoroughly combined.
Scatter the topping evenly over the rhubarb.
Bake the crumble until the top is golden and the filling is bubbling around the edges, 60 to 70 minutes.
Let cool slightly before cutting into serving pieces.
Serve with a generous scoop of buttermilk ice cream.