Name: Gluten-Free Coffee and Walnut Cake
Prep time: 25 min
Cook time: 20 min
Yield: 10 people
Ingredients: 200 g soft light brown sugar; 200 g unsalted butter (room temperature); 4 eggs (medium); 125 g teff flour; 100 g walnuts (plus extra to decorate); 50 g tapioca flour; 2½ teaspoons baking powder; ¼ teaspoon salt; 2 tablespoons instant coffee powder; 300 g unsalted butter (room temperature); 300 g icing sugar; 1 tablespoon instant coffee powder; 1/8 teaspoon salt