extra icing and decorations of your choice (see method section for ideas)
Heat oven to 160C/140C fan/gas 3. Line 2 x 12-hole muffin tins with paper cases. Put the eggs, yogurt, vanilla, sugar, flour, almonds and butter in your largest mixing bowl and beat until smooth and lump-free. Divide between the paper cases and bake for 25-30 mins (swapping the trays after 15 mins if you have to use 2 shelves) until a skewer poked into the centre of the cakes comes out clean. Cool on a wire rack. They can be frozen for up to 1 month or kept in an airtight container overnight.
To decorate, beat the butter and icing sugar together until smooth and light. Use a teaspoon to spoon a heaped dollop into the centre of each cake or, for speed, spoon into a food bag, cut about 2cm off the corner and pipe a dollop onto each.
Divide the icing into as many colours as you want - plus a piece left to be white, or to brush with glitter, if you like. Knead a little colouring into each piece until you have a good colour, then roll out onto a surface lightly dusted with icing sugar. Use a 6.5cm fluted cutter to stamp out rounds and press down onto the icing to flatten it a bit. Repeat with the other colours to cover all the cakes. Now decorate as you wish, or see our ideas, below.