Sugared Rhubarb Tart with Rye Crust

Name: Sugared Rhubarb Tart with Rye Crust
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 1 cup / 140g all-purpose flour; 1/2 cup and 2 tablespoons / 85g dark rye flour; 2 teaspoons Diamond Crystal kosher salt; 1 teaspoon granulated sugar (plus more for dusting); 3/4 cup / 170g salted butter (chilled); 4-5 tablespoons ice water; 1 tablespoon buttermilk; 1 pound fresh rhubarb (sliced at an angle ); 2 tablespoons freshly squeezed lemon juice (about 1 small lemon ); 1/3 cup granulated sugar; 2 tablespoons cornstarch; 1/2 cup heavy whipping cream; 2 tablespoons buttermilk; 1 tablespoon granulated sugar; Pinch of Diamond Crystal kosher salt