Preheat oven to 350 and line a muffin tray with cupcake liners
Beat together margarine and sugar until light and fluffy. It's important to get enough air into the mix at this stage as this will make for a nice light, crumbly sponge. The mix should be visibly lighter in colour and should look slightly aerated
Beat in the eggs, one at a time
Sieve the flour, baking powder, baking soda and salt into a large bowl then add a third of it to the batter and stir on low until combined. We're going to alternate the flour and milk additions to make sure it all incorporates properly
Once the first third of flour is totally mixed in, add half the milk and continue to mix on low. It's. important not to add the milk when there is still flour visible as this will cause a gloopy, glue-like mix in your batter.
Repeat this process with the next third of flour, the rest of the milk and then the last of the flour, making sure to combine everything in between each addition
Finally, add your vanilla extract and make sure everything is mixed together evenly
Scoop batter into cupcake liners and bake for 18 minutes or until a skewer inserted comese out clean
Cool entirely before decorating with your frosting of choice