Celestial Layer Cake with Blue and Purple Swirls

Ingredients

• 2 ½ cups all-purpose flour
• 2 ½ teaspoons baking powder
• ½ teaspoon salt
• 1 cup unsalted butter, room temperature
• 2 cups granulated sugar
• 4 large eggs, room temperature
• 1 tablespoon pure vanilla extract
• 1 cup whole milk, room temperature
• 1 ½ cups unsalted butter, room temperature
• 5 cups powdered sugar, sifted
• ¼ cup whole milk
• 2 teaspoons vanilla extract
• Gel food coloring: navy blue, purple, black, teal
• Edible glitter in silver, blue, or iridescent
• White fondant, optional for Pisces symbols or stars
• Silver star sprinkles, optional