Milk Bar Birthday Cake

Soften the butter, cream cheese, and eggs at room temperature, and preheat the oven to 180°C (350°F). Lightly grease a 28 cm x 28 cm square baking pan with butter and line it with parchment paper.

Sift together the flour, baking powder, and salt.

In a large bowl, beat the softened butter and granulated sugar on medium speed with a handheld mixer for 2–3 minutes, until the butter is slightly fluffy and pale in color.

Add the eggs one at a time, beating on medium-low speed after each addition until fully incorporated. Add the oil and mix on low speed until combined.

Reduce the mixer speed to low, slowly pour in the whole milk and vanilla extract, and continue beating for 3–5 minutes until smooth.

Add the sifted dry ingredients all at once and mix on low speed until just combined, with no visible dry flour. Fold in 50 g of rainbow sprinkles with a rubber spatula.

Pour the batter into the prepared pan, smoothing the surface with a spatula. Sprinkle the remaining 25 g of sprinkles on top. Bake in the preheated oven for about 25 minutes, or until a toothpick inserted in the center comes out clean. Transfer the cake to a wire rack to cool.

While the cake is baking, prepare the crumble. Mix all the dry crumble ingredients (except the oil and vanilla extract) in a bowl until evenly combined. Add the oil and vanilla extract and mix until incorporated.

Line a baking sheet with parchment paper, and drop 8–10 larger chunks of crumble (2–3 cm in size) onto the sheet, spreading the remaining crumble mixture evenly around them.

After the cake is done baking, bake the crumble in the oven at 150°C (300°F) for 15 minutes. Remove from the oven and let cool.

In a bowl, beat the softened butter and cream cheese with an electric mixer until smooth and fluffy. Add the salt and vanilla extract, mix briefly, and then add the icing sugar. Beat on low speed until the frosting is slightly fluffy, pale, and evenly textured.

In a separate container, mix the whole milk and vanilla extract until combined.

准Prepare a 6-inch cake ring or springform pan. Line the sides with a plastic cake collar for easy removal.

Cut out 2 full circles and 2 half-circles from the cake sheet. Place the two half-circles at the bottom of the ring to form the first layer. Brush 1/3 of the vanilla milk evenly over the surface of the cake. Spread a thin layer of frosting over the cake, sprinkle a layer of crumble, and spread another layer of frosting. Use a spatula or spoon to smooth the surface.

Place the second cake layer on top and repeat the same process with frosting and crumble. Place the third cake layer on top, brush with vanilla milk, and spread all the remaining frosting over the top, smoothing it out with a spatula.

Decorate the top with the reserved larger crumble chunks in a circle, and sprinkle a ring of rainbow sprinkles around the edges. Freeze the cake for at least 4 hours or overnight.

Before serving, transfer the cake from the freezer to the fridge 4 hours in advance. Remove the cake ring and plastic collar, and allow it to thaw in the fridge before enjoying.