Pre-heat the oven to 160C Fan/350F/Gas Mark 4 and grease and line a 2lb loaf tin
Mix together the butter or baking spread and caster sugar until light and fluffy, ideally using an electric mixer or a stand mixer with the paddle attachment
Add the eggs and vanilla extract, and mix in well
Fold in the self raising flour and sprinkles gently until fully combined
Pour the mixture into the loaf tin and bake for an hour, or until a skewer inserted in the centre comes out clean. Leave to cool fully
Make the buttercream by mixing the butter on it's own for a few minutes. Add the icing sugar, vanilla extract and milk, and mix until smooth. For the best results use a stand mixer with the paddle attachment. You can add a little extra milk if it is too stiff
Put the buttercream into a piping bag and pipe it onto the loaf cake, or spread on with a spoon or spatula
Decorate with sprinkles, if using. Store in an airtight container in a cool place and eat within 3 days. Or you can freeze it for up to 3 months
Video
Notes
Make sure all your ingredients (particularly the butter and eggs) are at room temperature before you start baking.
I used a baking spread for the cake and unsalted butter for the buttercream.
You can get the sprinkles I use from Sprinkles and Toppers, they are a little pricier than supermarket versions but this is because you get the best results. They retain their colour and are bake stable. You can also get them from Iced Jems.
For the best natural vanilla flavour, make sure to use an extract and not an essence. My favourite brand is Nielsen Massey.
You will need a 2lb loaf tin for this recipe (you can test the size of your loaf tin by seeing how much water the tin can hold, 2lb will hold about 2 pints/1100ml of water). If you have a 1lb loaf tin, simply halve the ingredient amounts.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50).
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.