Lemon Buttermilk Rhubarb Bundt Cakelets

Name: Lemon Buttermilk Rhubarb Bundt Cakelets
Ingredients: 2 & ½ cups plus 2 tablespoons(for rhubarb) all-purpose flour; 2 teaspoons baking powder; 1 teaspoon sea salt; 2 sticks (8 ounces) unsalted butter; 1 & ¾ cups sugar; Zest of 1 lemon, i used a meyer lemon; 3 eggs; ½ teaspoon lemon oil; ¾ cup buttermilk; 1 lb rhubarb (3 cups), trimmed and thinly sliced; 2 cups sifted powdered sugar, plus more as needed; 1 & ½ tablespoons lemon juice; 2 tablespoons buttermilk; 1 &1/2 tablespoons unsalted butter