Gluten Free Milk Bar Birthday Cake

Name: Gluten Free Milk Bar Birthday Cake
Prep time: 1 h 10 min
Cook time: 32 min
Total time: 1 h 42 min
Cuisine: American
Ingredients: 2/3 Cup Gluten Free 1-to-1 Flour Blend (I use Bob's Red Mill); 1/2 Cup Sugar; 2 Tablespoon Light Brown Sugar; 2 Tablespoon Rainbow Sprinkles; 1/2 teaspoon Baking Powder; 1/2 teaspoon Salt; 1/4 Cup Vegan Butter (melted); 1 teaspoon Vanilla; 1 3/4 Cup Gluten Free 1-to-1 Flour Blend (259 grams); 2 Tablespoon Arrowroot Powder (or Cornstarch); 2 teaspoon Baking Powder; 1/3 Cup Vegan Butter (room temperature); 1/3 Cup Olive Oil; 1 1/4 Cup Sugar; 1 1/2 teaspoon Vanilla; 3 Eggs (room temperature); 2/3 Cup Non-Dairy Milk (room temperature); 1/3 Cup Rainbow Sprinkles; 1/4 Cup Non-Dairy Milk; 1/2 Cup Vegan Butter; 4 ounces Vegan Cream Cheese; 2 teaspoon Vanilla; 1 1/4 Cup Powdered Sugar (sifted); 1/2 teaspoon Lemon Juice