- Why cream the butter and sugar?
- To incorporate air into the batter (creaming method). The sharp edges of the granulated sugar cut tiny bubbles into the butter, making the cake light.
- Can I use plain sugar for the decoration?
- The larger crystals of rock candy replicate the natural, irregular beauty and light refraction of minerals better.
Geode Cake
A meeting of nature and confectionery: this cake looks as if we've hidden a precious mineral, a geode, inside. The sparkling crystals are actually made of sugar, and the cavity of the cake is carved out with a knife. This is the high school of edible sculpture, but the technique can be mastered at home. The base is a massive, buttery sponge that withstands shaping.
Ingredients
300
g
Plain flour
250
g
Caster sugar (fine grain)
200
g
Butter (room temperature)
4
pcs
Eggs (large)
200
ml
Whole milk (3.5%)
12
g
Baking powder
2
g
Salt
400
g
Mascarpone or cream cheese
150
g
Icing sugar
200
ml
Double cream (cold)
1
tsp
Vanilla extract
150
g
Rock candy (clear/white)
1
set
Gel food colouring (blue, turquoise, gold)
1
capful
Vodka or clear spirit (for painting)
Shopping List (0)
Equipment Needed
- 2 x 20 cm cake tins
- Electric whisk
- Palette knife
- Sharp paring knife (for carving)
- Fine brush (for painting)
Allergen Information
Cereals containing gluten
Eggs
Milk
Instructions
1
✓
Preheat the oven to 180°C. Grease and flour the tins. Sift together the flour, salt, and baking powder.
Tip: Sifting aerates the flour and distributes the baking powder so there are no large holes in the cake.
2
✓
Cream the butter with the sugar until pale, then add the eggs one by one.
Tip: The eggs and butter should be the same temperature, otherwise the fat will separate (curdle) and the cake won't rise nicely.
3
✓
Alternately fold in the flour mixture and the milk. Do not overmix!
Tip: Gluten formation starts upon contact with flour. If you overmix, the cake will be chewy, not crumbly.
4
✓
Bake for 25-30 minutes (skewer test). Cool on a wire rack.
Tip: The wire rack allows air to circulate underneath, preventing a soggy bottom.
5
✓
Make the cream: whip the double cream, mix the mascarpone with the icing sugar, then fold together.
Tip: The fat droplets in the cream trap the air (foam). If you overbeat, the fat separates and becomes butter.
6
✓
Fill the cake and coat the outside. Chill.
Tip: The shape holds better during carving if the cream is cold.
7
✓
Cut a V-shaped hollow into the side. Coat the cut with cream and stick in the rock candy.
Tip: Use smaller and larger pieces for a natural effect.
8
✓
Paint the crystals with dye diluted with alcohol: darker inside, lighter outwards. Paint the rim gold.
Tip: Alcohol evaporates quickly and doesn't dissolve the sugar like water would.
Recipe FAQ
Ingredients
- 300 g Plain flour
- 250 g Caster sugar (fine grain)
- 200 g Butter (room temperature)
- 4 pcs Eggs (large)
- 200 ml Whole milk (3.5%)
- 12 g Baking powder
- 2 g Salt
- 400 g Mascarpone or cream cheese
- 150 g Icing sugar
- 200 ml Double cream (cold)
- 1 tsp Vanilla extract
- 150 g Rock candy (clear/white)
- 1 set Gel food colouring (blue, turquoise, gold)
- 1 capful Vodka or clear spirit (for painting)