Preheat the oven to 325° F / 160° C / 140° Fan / Gas 3.
Line a muffin tin with 12 large muffin sized cupcake cases.
Cream together the butter and sugar until pale and fluffy. Add the beaten eggs & the vanilla & mix beat together. Add the flour & cocoa and mix thoroughly until smooth. Then add the oil & milk and mix again until combined. Finally add the chocolate chips, and stir until well mixed.
Spoon the batter evenly into the cases and bake for 25-30 minutes.
When baked remove from the tin and leave to cool on a wire rack.
Whilst they cool cream the softened butter together with the vanilla and icing sugar, mixing together until creamy and lump free. Finally add some green colouring until it reaches a grassy colour.
Once the cakes are cool use a grass/fur tip to pipe buttercream onto each cupcake to resemble grass.
Make the bunny bottoms, feet and tails out of white fondant and stick the feet and tails to the bottoms by brushing them with a small amount of water and pressing them on.
Use the edible pen to draw the pads on the feet. Then colour a small amount of the remaining icing green and the rest orange.
Make the carrots from the orange icing and make some leaf shapes from the green and stick them on top of the carrots with water.
Finally stick the bunny bottoms and carrots onto the grassy cupcakes.