Retro Christmas Tree Cake

Name: Retro Christmas Tree Cake
Cook time: 2 h 30 min
Total time: 2 h 30 min
Cuisine: American
Ingredients: Baking spray with flour; 1 1/2 c. all-purpose flour, spooned and leveled; 2 tsp. baking powder; 1/2 tsp. kosher salt; 1/2 c. (1 stick) unsalted butter, at room temperature; 1 c. granulated sugar; 2 large eggs, at room temperature; 1 tsp. pure vanilla extract; 2/3 c. whole milk, at room temperature; 2 c. (1/2 pound) confectioner's sugar, sifted; 1/2 tsp. salt; 2 tbsp. milk; Orange, red, green, blue, and yellow fondant