Preheat the oven to 170°C (340°F).
Lightly butter and line a 20 x 20 cm (8 x 8 in) square cake tin. Mix the cocoa powder, vanilla extract and boiling water in a small bowl until combined, then set aside to cool. Into a clean bowl sift the flour, baking powder and salt, stir to combine and set aside.
Using a food processor with the beater attachment, beat the butter and sugars for 3–4 minutes, or until the mixture is pale and creamy. Add the eggs to the butter mixture, beating well after each addition. Add the milk, plus the cocoa and flour mixtures, and continue to beat. Scrape down the sides of the bowl to make sure that all of the ingredients are well incorporated.
Pour the mixture into the prepared tin and bake for 20–25 minutes, or until a skewer inserted into the cake comes out clean.
Remove from the tin and set the cake aside to cool on a wire rack. To make the ganache, place the chopped chocolate in a bowl. Heat the cream in a saucepan until it is bubbling, and then pour the cream over the chocolate. Whisk until it is completely smooth and all of the chocolate has melted. Set aside to cool, then chill for 20 minutes, or until thickened. Once your chilled ganache has thickened, beat with a spatula until it is smooth.
To assemble the cakes, cut out small shapes using a round 3 cm (1 in) cutter. Use a spatula or knife to frost the cakes with the ganache. Place each cake in a mini cupcake case and decorate with a mini chocolate egg. Store in a tin or an airtight container in the fridge for up to three days. Serve at room temperature.
This recipe is excerpted with permission from <a href="http://www.amazon.com/gp/product/1742706347/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1742706347&linkCode=as2&tag=craftfocom-20">"trEATs: Delicious Food Gifts to Make at Home"</a> by April Carter and published by Hardie Grant Books.