Mint Slice Cake

At the risk of being a one-cake-gimmick wonder, I'm posting yet another biscuit-inspired cake. Think of it as a thank you cake for the amazing response to my Tim Tam Cake. I seriously didn't expect it but I guess everyone loves Tim Tams/chocolate cake so it's not too unbelievable. This Saturday is my best friend Asian Gaga's birthday. You might remember that for her last birthday I attempted my infamous Lady Gaga Cake, the photos of which make me cringe but she loved it. This year she asked if I could make the Tim Tam Cake for her, but could I make it smaller and mint flavoured? So I thought, why not just make a Mint Slice Cake? The Mint Slice (it doesn't have its own wiki page, aww.) is basically a chocolate biscuit with a thick layer of peppermint icing on top and the whole thing is covered with a layer of dark chocolate. It might not be as popular as the Tim Tam but it's always been a favourite of mine, thanks to my love of dark chocolate and peppermint and the awesome ratio of icing to biscuit.

Originally I wasn't going to blog about it but I liked how the photos turned out. My blog was pretty quiet this week and I didn't want to leave it neglected for the whole weekend too! So I'm going to keep this short and sweet - the cake uses the same sponge cake and ganache recipe as the Tim Tam cake, which are both halved in quantity, and the chocolate in the butter icing filling is replaced with peppermint essence so that it's fluffy, white and minty. It was actually harder to make this one resemble the biscuit, the Tim Tams had those recognisable ripples on their surface but the Mint Slice is completely smooth. I suck at keeping ganache smooth. I did my best. The important thing is it tastes great! HAPPY BIRTHDAY ASIAN GAGA!!! I love you, crazy lady.

Mint Slice Cake
(adapted from my Tim Tam Cake, sponge recipe from Gourmet Traveller)
2 large eggs
55g (¼ cup) caster sugar
32g cornflour (cornstarch)
17g Dutch-process cocoa
2 tsp plain flour
½ tsp cream of tartar
¼ tsp bicarb soda
25g unsalted butter, melted and cooled

For the mint icing:
100g butter, removed from the fridge 30 minutes before starting
3 cups icing sugar, sifted
2 tsp milk
2 tsp peppermint essence
Optional: Mint Slice biscuits to hide in this layer, I only hid one for fun so it's definitely not needed

For the chocolate ganache topping:
150ml pouring cream (min. 35% milk fat pure cream)
200g dark chocolate (I used 60% cocoa)

Grease and line one 20cm round cake tin. Preheat oven to 180°C (350°F). Whisk eggs and sugar in an electric mixer until thick and pale (5-6 minutes). Sift over cornflour, cocoa, flour, cream of tartar and bicarb soda, fold in with spatula. Fold in butter, spoon into prepared tin. Bake in centre of oven until cake springs back when lightly pressed (10-12 minutes). Turn onto baking paper covered wire rack and cool completely.

Prepare the mint icing; beat butter and icing sugar together until light and fluffy, then add mint essence and milk and beat until smooth. Spread over the top of cake and smooth with a spatula. To make the ganache, place cream in a small saucepan on low heat. Just as it starts to come to the boil, remove from the heat and cool for a couple minutes. Pour hot cream over chocolate and set aside 10 minutes to allow chocolate to melt. Mix cream and chocolate together until smooth using a whisk, then cool (I placed mine in the fridge for about 10 mins) until it reaches room temperature and thickens. Pour over the top of the cake, using a spatula to ensure the ganache covers all the top and sides of the cake (the excess will drip off everywhere so make sure you lay down some baking paper to catch the drips). Chill in the fridge until the ganache sets, then peel off the bottom baking paper and serve cake at room temperature.