Bolu Gulung (Rainbow Swiss Roll)
Equipment
- Stove top steamer
- Rectangular baking pan (as shown)
- Parchment paper
- Cooking oil
- Ziplock bags or piping bags
Ingredients
Cake
- 75 g sugar
- 3 yolks
- 2 egg whites
- 1/2 tsp emulsifier such as Sp, Ovalet, VX - can be purchased at specialty store for bakers, online, and/or Asian stores
- 1 tsp vanilla essence
- 40 g flour
- 5 g cornstarch
- 5 g milk powder I got mine full cream at Bulk Barn. You can use skim milk powder from Walmart or even coffee creamer
- a pinch of salt
- 50 ml oil
- food color I use 5 differ colors
Buttercream
- 60 ml pasteurized egg whites
- 226 g icing sugar
- 1 lb unsalted butter
- a pinch of salt
- 1 tbsp vanilla essence subs with other flavor according to your liking!
Instructions
Cake
- Preheat steamer for about 15 minutes on high heat then turn heat to super low
- In a bowl, mix dry ingredients (flour, salt, milk powder, cornstarch)
- In a separate bowl, beat yolks, egg whites, sugar, emulsifier, vanilla essence until fluffy and thickened, over high speed
- Lower speed to medium and beat in flour mixture
- Beat in oil until combined well
- Divide batter into 5 bowls and add food coloring into each bowl
- Pour each colored batter into ziplock bags and snip the corner
- Pipe batter alternating one to another on parchment lined baking pan which already greased with oil
- Turn up oven heat to high again and steam cake for 10 minutes
- On table, place a clean parchment paper and turn over steamed cake on paper
- Peel off paper from cake that was used for steaming
- Roll cake slowly and let it stand for 10 minutes
Buttercream
- Mix egg whites with icing sugar then beat to combine
- Beat in butter a little at a time until fluffy and creamy
- Beat in a pinch of salt followed with vanilla essence
Swiss Roll
- Unroll cake and spread buttercream
- Reroll cake and slice to serve