The rhubarb is sour, the matcha is earthy, and the lemon is acidic—but somehow, together, they all work. Especially when drizzled with a Greek yogurt icing that's as tangy as a cream cheese glaze but easier to whisk together as your cake cools.
This cake recipe is adapted from The Pastry Affair's Rhubarb-Vanilla Pound Cake.
Generously grease a loaf pan (don't skimp; you can also line it with a parchment sling if that makes you more comfortable) and heat the oven to 350° F with a rack in the center.
Mix the rhubarb with 1/4 cup of sugar and place in a medium skillet or sauce pan. Turn the heat to medium and cook, stirring often, until the sugar and rhubarb juices melt into a syrup and the rhubarb chunks are fork-tender, about 5 minutes. Do not over-cook the rhubarb (it shouldn't be mushy, watery, stewy, or soupy) or it will disappear into the cake. Set aside to cool.
In the bowl of a stand mixer fitted with a paddle attachment, mix the remaining 1 1/4 cups sugar with the lemon zest until moist and fragrant. Add the butter and cream it with the lemon-sugar until fluffy and pale, 3 to 5 minutes. Add the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl. Add the vanilla and 1/3 cup of the Greek yogurt and mix until combined.
Whisk the flour, matcha, baking powder, and salt together in a separate bowl. Add to the wet ingredients and mix until the dry ingredients have just disappeared. Fold in the rhubarb with a spatula. Transfer to the greased pan. Bake for 55 to 70 minutes, until a cake tester inserted into the middle of the loaf comes out clean. Allow to cool before turning it out of the pan.
Meanwhile, make the glaze: Whisk the remaining 1/3 cup Greek yogurt with the confectioners' sugar, the lemon juice, a pinch of salt, and 1/2 teaspoon water until smooth. Drizzle over the cake and allow to set for about 30 minutes before slicing and serving.