Pineapple Cupcakes with Pineapple Buttercream

Name: Pineapple Cupcakes with Pineapple Buttercream
Cuisine: American
Ingredients: 1 cup (2 sticks) unsalted butter, room temperature; 1.75 cups sugar; 4 large eggs; 1 teaspoon vanilla; 1.5 cups all purpose flour; 1.5 cups cake flour; 0.5 teaspoon salt; 1 teaspoon baking powder; 1 teaspoon baking soda; 1 cup milk; 20 ounces canned pineapple in juice, juice reserved.; 0.25 teaspoon salt; 8 ounce can crushed pineapple, in juice; 5-6 cups powdered sugar