Retro Hummingbird Cake

Name: Retro Hummingbird Cake
Ingredients: Nonstick baking spray with flour; 113g raw pecan halves (4 ounces; 1 cup), plus more for decorating; 350g granulated sugar (12 1/4 ounces; 1 3/4 cups); 200g neutral oil, such as vegetable (1 cup; 240ml); 3 large large eggs; 2 teaspoons vanilla extract; Two 8-ounce cans crushed pineapple in juice, undrained (about 1 3/4 cup); 4 small overripe bananas (about 4 1/2 ounces; 125g each unpeeled); 345g bleached cake flour (about 12 ounces; 3 cups); 1 1/2 teaspoons ground cinnamon; 1 1/2 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume; 1 teaspoon baking soda; 3/4 teaspoon baking powder; 1/4 teaspoon ground allspice; Two 8-ounce packages cream cheese, at room temperature; 226g unsalted butter (8 ounces; 1 cup), at room temperature; 400g powdered sugar (14 ounces; 3 1/2 cups), sifted; 1 tablespoon (15ml) reserved pineapple juice (see below); 1 teaspoon vanilla extract