Preheat oven to 350 degrees F (180 degrees C). Line three 8-inch pans and three 6-inch round pans with parchment rounds, and grease with
Non-Stick Baking Spray (as needed)
All-Purpose Flour (4 3/4 cups)
Granulated Sugar (4 1/2 cups)
Baking Powder (1 Tbsp)
Salt (1/2 Tbsp)
in a stand mixer with a paddle attachment until fully combined.
Mix chunks of room-temperature
Unsalted Butter (1 1/2 cups)
slowly into the dry mix, at a low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.
Pasteurized Egg Whites (1 1/2 cups)
, and mix on low until just incorporated. Mix in the
Buttermilk (2 1/4 cups)
in two installments, at a low speed.
Vanilla Extract (1 Tbsp)
Vegetable Oil (2 Tbsp)
, and mix at a low speed until just combined. If needed, scrape down the sides of the bowl with a spatula, then beat on low speed for about 15 seconds.
Divide batter evenly between the prepared cake pans using a spatula (fill each pan about 1-inch high with batter). Bake for 30-35 minutes, or until a toothpick comes out clean.
While the cake layers bake and cool, make the Vanilla Buttercream Frosting. Beat the
Unsalted Butter (4 cups)
on medium speed for 30 seconds with a paddle attachment, or until smooth.
Slowly add in the
Powdered Confectioners Sugar (16 cups)
, 1 cup at a time. Alternate with small splashes of
Heavy Cream (1/2 cup)
Once fully mixed, add in the
Vanilla Extract (2 Tbsp)
Salt (1/2 Tbsp)
, and beat on low until the ingredients are fully incorporated, and a thick but spreadable consistency is reached.
In the center of both cake boards, cut star-shaped slits. Pierce the center of the wooden dowel. One at a time, pierce the center with the wooden dowel to ensure the hole is big enough. Make sure the dowel is 1-inch taller than the bottom layer of the cake.
Prepare to frost each tier with a greaseproof cake board on the bottom. To ensure the layers stay in place use a dab of frosting to help stick the first cake layer to the board.
Stack the three 8-inch cake rounds and add an even layer of buttercream between the cake layers.
Apply a thin coat of frosting around the cake, to fully cover the cake layers. Smooth using a bench scraper, then chill the cake in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.
While the 8-inch rounds are chilling, prepare the second tier. Add an even layer of buttercream between the cake layers.
Then coat frosting around the cake, to fully cover the cake layers. Smooth using a bench scraper. Chill the cake in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.
Trim 4 bubble tea straws to be the exact height of the tier, and insert them into the cake, to help support the top tier. Place them an even distance apart, about 2 ½-inches from the center of the cake.
Once the straws are in place, pierce the center of the cake with the wooden dowel. Carefully slide the 6-inch tier of cake over the dowel, until it rests on the 8-inch tier.
Trim the stems of each flower to be 1-inch long. Wrap the flower stem and part of the wire with floral tape. Start at the flower and wrap until the end of the stem creating a point with the tape.
Fill in the bottom of the top tier with frosting. Pipe two rings of frostings over the top and the lower ring of the cake.
Insert the flowers into the ledge of the 8-inch tier and on top of the cake.