Matcha White Chocolate Lamingtons

Method

1. Preheat the oven to 180 °C (160 °C fan). Lightly butter a 10×10 cm tin and line the base and two sides with an overhanging strip of baking paper. Beat the egg; if you need half an egg, beat a whole one and use half (about 25 g).

2. Beat the softened butter and sugar with an electric mixer for 3 min until pale and fluffy, then beat in the egg in two additions, mixing well after each.

   Add in this stepButter, softened (for the cake) 40 gCaster sugar 50 gEgg, at room temperature, beaten 1

3. Sift the flour, cake matcha, baking powder and salt together. Matcha clumps easily, so sifting is a must or you'll get green specks. Fold the dry mix and milk in alternately with a spatula (starting and ending with flour), only until no dry flour remains. Pour into the tin and level the top.

   Add in this stepPlain flour 75 gMatcha powder (for the cake) 1 tspBaking powder ¾ tspSalt 1 pinchMilk, at room temperature (for the cake) 40 ml

4. Bake on the middle shelf of the preheated oven for 20 min, until it springs back when pressed and a skewer comes out clean. The matcha may make the outside look a little darker; that's fine. Cool in the tin for 10 minutes, lift out and cool completely, then wrap in cling film and chill for at least 1 h.

   oven

5. Toast the black sesame seeds in a dry frying pan over medium-low heat for 2 min, shaking the pan. As soon as they smell nutty and start to pop, tip them onto a wide plate to cool, then mix them evenly through the coconut.

   Add in this stepBlack sesame seeds 2½ tspDesiccated coconut 70 g

   medium-low heat

6. Trim the edges of the cold cake and cut it into 5 cm squares; you will get 4 pieces. Heat 3 cm of water in a saucepan over low heat until just steaming, then turn off the heat. Put the white chocolate and milk in a heatproof bowl over the pan and stir slowly for 3 min until melted. White chocolate seizes and splits if it gets too hot, so the water must not boil. Once smooth, sift in the icing sugar and matcha and whisk to a glossy pale-green icing. It should thinly coat the back of a spoon and flow; if too thick, add warm milk a teaspoon at a time.

   Add in this stepWhite chocolate, finely chopped 50 gMilk (for the icing) 45 mlIcing sugar 80 gMatcha powder (for the icing, a bright green one) 1½ tsp

   low heat

7. Hold a square on two forks, dip it in the icing and turn quickly to coat all sides, hold it up for 2 to 3 seconds to drip, then roll it in the sesame coconut, spooning it over every side. Place on a rack, repeat with the rest and chill for 20 min until the icing sets. White chocolate icing sets better in the fridge than at room temperature.