Preheat oven to 350 degrees F (180 degrees C). Line a 9-inch round cake pan with parchment paper or oil and flour pan well; set aside.
Cream Butter (6 tablespoon) and Granulated Sugar (3/4 cup) until light and fluffy (about 7-10 min).
Meanwhile, combine Milk (3 tablespoon), Egg (3), and Vanilla Extract (1 teaspoon) in a small bowl and set aside.
Sift together Bob's Red Mill® Super-Fine Unbleached Cake Flour (1 1/2 cup), Baking Powder (1 1/2 teaspoon), and Salt (1/4 teaspoon) and set aside.
Add 1/3 of the flour mixture to the butter and briefly mix to combine, followed by 1/2 of the liquid. Continue to alternately add remaining flour and liquid and mix until combined, taking care not to over-mix the batter.
Transfer batter to the prepared cake pan and spread to evenly fill pan and smooth top. Bake until set and toothpick inserted in the center comes out clean, about 25-30 min. Let cool thoroughly, at least 1 hour. Meanwhile, prepare frosting.
Combine Powdered Confectioners Sugar (4 1/2 cup) and soften Butter (24 tablespoon) and mix on low for 1 minute to combine. Increase speed to medium and mix until light and fluffy, 3-5 minutes.
Add Vanilla Extract (1 tablespoon) and Whole Milk (1/2 cup), mix until combined, about 1 minute more. Set aside frosting and shredded coconut until ready to assemble cake.
Divide cake in half down the center. Spread a generous layer of frosting on one half of the cake.
Flip the unfrosted half over onto the frosted half so the halves line-up evenly.
Cut out a small (about 1-inch) notch about 1/3 of the way up one end of the body and about 1/3 of the way into the cake towards the center. Flip the notch over and attach to the opposite end of the cake with frosting to create a tail.
Frost entire cake, adding extra frosting to the sides of the bunny "body" to form a rounded shape.
Sprinkle Bob's Red Mill® Shredded Coconut (3 cup) over the cake, pressing in lightly to secure. Add paper ears and a tiny pink nose, if desired. Enjoy!