Ingredients
Method
- For the matcha cake:
- Preheat your oven to 180°C / 160°C fan / 350°F / gas mark 4.
- Grease two 15cm (6 in) cake tins thoroughly, and line their bases with some greaseproof or parchment paper.
- Measure your butter/margarine and sugar into a large bowl.
- Beat well with a freestanding mixer, electric whisk, or wooden spoon, until light and fluffy. This should take 1-2 minutes.
- Add the eggs one at a time, mixing well between each addition.
- Add the flour and matcha powder and stir gently until just smooth and combined into a thick green batter.
- Pour the mixture evenly between the 2 tins and bake in the preheated oven for 25-30 minutes or until risen, and a skewer inserted into the centre can be cleanly removed.
- Allow the cakes to cool in their tins for about 15 minutes before removing them and allowing them to cool completely on a wire rack.
- For the white chocolate frosting:
- In a large bowl, beat together all the frosting ingredients, except the matcha powder (if using), until you have a fluffy white frosting. This can take up to 5 minutes.
- If you would like to have a pale green marble to the frosting, halve the frosting and mix the matcha powder with one half. This way you can play around with the white and pastel green shades!
- To assemble:
- Set a small frying pan over a medium heat.
- Tip your pistachios into the pan, rolling them around in the dry heat for up to 8 minutes. By this point you should smell their delicious savouriness, but not burnt bitterness!
- Allow the nuts to cool for 5 minutes before chopping into small pieces.
- Once all components have been prepared, place one cake onto your serving plate and slather the top with some of your frosting.
- Scatter over half of your chopped pistachios.
- Top this with the second cake layer.
- Spread or pipe your remaining frosting all over the top and sides of the cake, decorating however you like with the remaining pistachios.
- Slice up and enjoy!
Notes
Matcha Quality Matters: I find that using a good quality culinary-grade matcha makes all the difference here.
Cheaper ones can turn bitter and muddy, so I always reach for a vibrant green powder from a trusted tea shop.
Butter Temperature is Key: When creaming the butter and sugar, make sure your butter is properly softened to room temperature.
If it's too cold, the mixture won't get light and fluffy, and your cake will be dense.
I usually take mine out an hour before baking.
Mascarpone for Stability: I love using mascarpone in the frosting because it adds a lovely tang and helps stabilize the white chocolate, preventing it from being too sweet or runny.
Don't swap it for more butter or cream cheese unless you're after a different texture.
Toasting Pistachios: Toasting the pistachios in a dry pan is a step I never skip.
It brings out their natural oils and a deep, savory note that balances the sweet cake.
Just watch them closely as they can burn in seconds.
Make Ahead Friendly: This cake actually tastes better the next day.
I often bake the sponges a day ahead, wrap them tightly in cling film, and store them at room temperature.
The frosting can be made a day in advance too and kept in the fridge, just give it a good stir before using.
Slicing for Clean Cuts: For perfect slices, I chill the assembled cake in the fridge for about 30 minutes before cutting.
Use a sharp, thin-bladed knife and wipe it clean between each slice for neat, professional-looking pieces.
Storage Tip: If you have leftovers, store them in an airtight container in the fridge for up to three days.
The cake stays moist, and the frosting holds its shape beautifully.
Let slices sit at room temperature for ten minutes before serving to soften the buttercream.
