Preheat the oven to 160C. Grease & flour a 7-inch baking tin; set aside.
In a large bowl, sift together the flour, baking powder, bicarbonate of soda, cocoa powder, & sugar. Mix together with a whisk.
Add the butter, milk, eggs & vanilla extract into the bowl & use an electric beater to mix until just combined – being careful not to overmix the batter. Use a spatula to scrape down the sides of the bowl & to gently fold together any excess flour.
Bake in the preheated oven for 25-35 minutes, or until a skewer inserted into the centre of the cake comes out clean with some moist crumbs. Leave the cake to cool in the tin for 5-minutes, before turning out onto a wire rack to cool completely.
To make the frosting, use an electric whisk to combine all of the ingredients – cream cheese, butter, milk, sugar, cocoa powder, vanilla extract – in a large bowl.
When the cake has cooled, pile all of the frosting on top & use an offset spatula to spread evenly over the surface and sides of the cake.
Enjoy in large slices with a cup of coffee while looking out at the snow falling down.