Soft and moist baked sponge cakes topped with delicious old-school buttercream frosting and with three different topping varieties like shredded cheese, chocolate sprinkles, and peanuts are popular cakes in Indonesia and other Southeast Asia countries.
Bolu jadul is a nostalgic cake that has a special place in my heart or pretty much most kids who grew up during my time and before. I remember my dad liked to go to bakery shops and got a few slices of bolu jadul. His favorite was chocolate. I like the cheese and peanuts one because I just love the combination of sweet and slightly savory in cakes and desserts.
What is bolu jadul?
Bolu jadul is a term used in Indonesia to refer to a type of traditional cake that was popular in the past. “Bolu” usually refers to sponge cake, while “jadul” (a short for Jaman Dulu) is a colloquial term that means “old-fashioned” or “vintage”. Sometimes, bolu jadul is also referred to as cake potong (cake slices) because they are usually cut into slices and put in decorative paper cups.
The cake is prepared with basic sponge cake ingredients and then topped with traditional buttercream frosting. The popular toppings in Indonesia are shredded cheese (bolu jadul keju) and chocolate sprinkles/jammies/chocolate rice (bolu jadul meses coklat). Chopped peanuts (bolu jadul kacang) are also one of my favorite toppings, though not as popular as the formers.
In Singapore and Malaysia, the old-school sponge cake with buttercream is fancier. They are two layers and also frosted with buttercream and decorated with some old-school piped flower designs, colorful piping gel, sprinkles, etc. They are usually also sold in slices.
How to make bolu jadul
1. Preheat oven to 350 F (180 C) for conventional oven, 330 F (165 C) for convection oven. Line the bottom and side of the pan with parchment paper for easier removal later. Sift cake flour, milk powder, cornstarch, baking powder, and salt and mix to combine. Sifting will get rid of the lump when you fold the flour into the cake batter later
2. Put eggs, sugar, and vanilla extract in a mixing bowl. Beat on medium speed (speed 4 on KA) for 1 minute using a whisk attachment and then increase to high speed (speed 8). Beat until the mixture is thick, creamy, and pale. When you lift the batter with the whisk, the batter that drops down will leave a trail that remains visible for about a minute before slowly disappearing. You have to beat it to this ribbon stage or the cake will not turn out right
3. Once it has reached the ribbon stage, turn off the mixer. Add 1/3 of the flour mixture and very gently but work efficiently, fold the flour mixture into the batter using a rubber spatula using a swipe-down and fold-over method. Then add the next batch of flour and continue to fold
4. Once you no longer see any loose flour in the batter, scoop out about 1/3 cup of the batter into a different bowl. Add oil and stir to combine thoroughly. 
5. Pour this mixture gently over the batter and use a spatula to fold again until combined. Make sure they are thoroughly combined into the batter or your cake will have separate layers later
6. Pour the well-combined batter into the prepared pan. Use a skewer and do a zig zag pattern on the batter to pop any large bubbles. Place the pan on the middle rack and bake for 25-30 minutes or until the cake tester inserted comes out clean.
7. Remove the cake from the oven and set on a cooling rack to let it cool completely. The cake is ready to be frosted once they have cooled down completely.
8. Place a softened room temperature butter in a mixing bowl along with the sugar. Whip on medium speed (speed 6 on KA) until the mixture is pale and creamy. Add condensed milk and whip again until it’s fully combined. The buttercream texture should be smooth, creamy, and easily spreadable
9. Once the cake has cooled down completely, spread the buttercream frosting evenly on top of the cake. Sprinkle with the topping of your choice. Cut into 16 slices and put on decorative muffin cup liners if you want to. Store the leftover cakes in an air-tight container in the fridge for 2-3 days. The longer you keep them in the fridge, the drier the texture becomes. So keep that in mind
Did you make this old-school buttercream cake slices/bolu jadul recipe?
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Bolu Jadul (Old-School Buttercream Cake Slices)
Ingredients
Cake batter:
- 200 g eggs room temperature (about 4 large eggs)
- 100 g sugar
- 1 tsp vanilla extract
- 80 g cake flour
- ½ tsp baking powder
- 10 g milk powder
- 10 g cornstarch
- Small pinch of salt
- 90 g melted butter
Easy buttercream frosting:
- 200 g unsalted butter
- 80 g icing sugar
- Pinch of salt
- 30 g condensed milk
Topping: (You can choose any one of these or use your own imaginations)
- 150 g Shredded cheese or more if you want more
- Chocolate sprinkles
- Roasted peanuts roughly chopped
Instructions
- Preheat oven to 350 F (180 C) for conventional oven, 330 F (165 C) for convection oven.
- Line the bottom and side of the pan with parchment paper for easier removal later
- Sift cake flour, milk powder, cornstarch, baking powder and salt and mix to combine. Sifting will get rid of the lump when you fold in the flour into the cake batter later
Prepare the cake batter:
- Put eggs, sugar, and vanilla extract in a mixing bowl. Beat on medium speed (speed 4 on KA) for 1 minute using a whisk attachment and then increase to high speed (speed 8). Beat until the mixture is thick, creamy, and pale. When you lift the batter with the whisk, the batter that drops down will leave a trail that remains visible for about a minute before slowly disappearing. You have to beat it to this ribbon stage or the cake will not turn out right
Fold the flour mixture into the batter:
- Once it has reached the ribbon stage, turn off the mixer. Add 1/3 of the flour mixture and very gently but work efficiently, fold the flour mixture into the batter using a rubber spatula using a swipe down and fold over method. Then add the next batch of flour and continue to fold.
Fold the oil mixture into the batter:
- Once you no longer see any loose flour in the batter, scoop out about 1/3 cup of the batter into a different bowl. Add oil and stir to combine thoroughly. Pour this mixture gently over the batter and use a spatula to fold again until combined. Make sure they are thoroughly combined into the batter or your cake will have separate layers later
Baking:
- Pour the well-combined batter into the prepared pan. Use a skewer and do a zig zag pattern on the batter to pop any large bubbles. Place the pan on the middle rack and bake for 25-30 minutes or until the cake tester inserted comes out clean.
Cool down:
- Remove the cake from the oven and set on a cooling rack to let it cool completely. The cake is ready to be frosted once they have cooled down completely.
Prepare buttercream frosting while waiting:
- Place a softened room temperature butter in a mixing bowl along with the sugar. Whip on medium speed (speed 6 on KA) until the mixture is pale and creamy. Add condensed milk and whip again until it's fully combined. The buttercream texture should be smooth, creamy, and easily spreadable
Assembling:
- Once the cake has cooled down completely, spread the buttercream frosting evenly on top of the cake. Sprinkle with the topping of your choice
- Cut into 16 slices and put on decorative muffin cup liners if you want to. Store the leftover cakes in an air-tight container in the fridge for 2-3 days. The longer you keep them in the fridge, the drier the texture becomes. So keep that in mind
Storing:
- If you haven't cut the cake, you can freeze the entire frosted cake. Put it in the freezer for the frosting to firm up for about one hour. Then wrap the cake in double cling wrap, pushing as much air out as possible. Store in freezer container if you have one. They can be kept for a month in the freezer. When you are ready to serve it, thaw it overnight in the fridge and then slice into serving portions
- If you have sliced the cake, arrange them on a baking sheet and put in the freezer for one hour to firm up the frosting. Then wrap in double layer of cling wrap and put in freezer-friendly container or bag and they can be kept frozen for one month. Simply thaw overnight in the fridge or at room temperature before serving
