Cream together the butter and sugar until light and fluffy. Beat in the eggs, stir in the colouring, yogurt and vanilla extract. Fold in the flour and cocoa powder.
100 g unsalted butter, 155 g caster sugar (superfine sugar), 2 medium free-range eggs, 175 g self-raising flour, red gel colouring, 200 g Greek style natural yogurt, 1 tsp vanilla extract, 30 g cocoa powder
Butter your crock pot and line with grease proof paper or a large cake case.
Cook on high for approx 1.5 to 2 hrs until a skewer comes out clean. Put a tea towel under the lid to catch moisture during cooking.
Remove from the slow cooker and allow to cool completely.
To make the icing, use a hand mixer to mix the butter or margarine until it is soft an fluffy.
100 g unsalted butter (or margarine)
Add the icing sugar bit by bit, mixing until each part is fully combined. Once you have added all the icing sugar, continue to mix for a few minutes until light and fluffy.
200 g icing sugar
Add the vanilla bean paste (this adds wonderful vanilla speckles to the icing) and milk and mix again until fully combined and still light and fluffy.
1 tsp vanilla bean paste, 0.5 tsp milk
Split the cooled cake, and fill with buttercream and spread a layer on top.
Serve and enjoy!