Harvey Wallbanger from Scratch

Name: Harvey Wallbanger from Scratch
Ingredients: 1 3/4 cups (347g) sugar; 8 tablespoons (113g) unsalted butter at room temperature at least 65°F; 3/4 teaspoon salt; 1/3 cup (57g) vegetable oil; 2 teaspoons vanilla extract; 4 large eggs at room temperature; 3 cups (361g) King Arthur Unbleached All-Purpo; 3 tablespoons (21g) cornstarch; 1 tablespoon + 1 teaspoon baking powder; 3/4 cup (170g) orange juice; 1/4 cup (57g) Galliano; 1/4 cup (57g) vodka; 1 tablespoon orange zest; 1 cup (113g) confectioners' sugar sifted; 1 tablespoon (14g) orange juice; 1 tablespoon (14g) Galliano; 1 teaspoon vodka; generous pinch of salt