Name: Family-sized funfetti slab cake recipe
Prep time: 25 min
Cook time: 35 min
Total time: 60 min
Yield: 20
Ingredients: 625.00 ml plain flour; 1 tsp baking powder; 1/2 tsp bicarb soda; pinch salt; 190g butter, softened; 312.50 ml caster sugar; 62.50 ml vegetable oil; 4 eggs; 250.00 ml buttermilk; 4.00 tsp vanilla essence; 125.00 ml funfetti sprinkles; 150g butter, softened; 750.00 ml icing sugar, sifted; 62.50 ml cream; Yellow food colouring; 1-40.00 ml funfetti sprinkles

by Greer Worsley Last updated on 10/05/2022

This funfetti slab cake is big enough to feed a big family, and is a great celebration cake for birthdays or anniversaries. Just add candles! - Greer Worsley

Ingredients

2 1/2 cups plain flour
1 tsp baking powder
1/2 tsp bicarb soda
pinch salt
190g butter, softened
1 1/4 cups caster sugar
1/4 cup vegetable oil
4 eggs
1 cup buttermilk
2 tsp vanilla essence
1/2 cup funfetti sprinkles

For frosting

150g butter, softened
3 cups icing sugar, sifted
1/4 cup cream
2 tsp vanilla essence
Yellow food colouring
1-2 tbsp funfetti sprinkles

Method

Step 1

Preheat oven to 160C conventional. Grease a 23cm x 32cm deep baking dish or sheet pan and line it with baking paper.
Step 2

Place flour, baking powder, bicarb soda and salt in a bowl and whisk to combine.
Step 3

In the bowl of a stand mixer or using hand-held beaters, cream butter and sugar for 4-5 minutes until very pale and creamy. Add oil and mix well. Add eggs one at a time, beating well between each addition. Add the flour mixture, buttermilk and vanilla, and mix until just combined. Fold through funfetti sprinkles. Pour batter into prepared tin and smooth down the top. Bake for 35-40 minutes until a skewer inserted into the centre comes out clean. Allow to cool slightly in the pan then turn out onto a rack to cool completely.
Step 4

To make frosting, beat butter in a stand mixer or using hand-held beaters until soft and pale. Add icing sugar in two batches, and beat to combine. Add cream and vanilla and continue beating for 2-3 minutes until very soft and fluffy. For a pale yellow frosting, you can add a drop or two of yellow food colouring if required (a regular buttercream will already be a pale shade of yellow depending on the colour of the butter.)
Step 5

Place cake on a board and use a serrated knife to cut a thin straight layer off all of the side edges. Spread about a third of the frosting on top of the cake. Add remaining frosting to a piping bag fitted with a star nozzle. Pipe swirls around the perimeter of the cake. Sprinkle with extra funfetti sprinkles.