Line 18 sections of 2 x 12-section bun trays with paper cake cases. Put the butter, caster sugar, eggs, flour, cocoa powder and baking powder in a bowl and beat with a hand-held electric whisk for about a minute until light and creamy. Divide the cake mixture between the paper cases.
Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes or until risen and just firm to the touch. Transfer to a wire rack to cool.
Beat together the ricotta, brandy, icing sugar and cream in a bowl. Gently stir in the chocolate, almonds and cherries.
Cut a thick diagonal slice off the top of each cake and pile the filling on to the cut surfaces. Reposition the slices, twisting them so that the thickest part is uppermost. Serve within 24 hours, dusted with cocoa powder.