Pre-heat the over to 180 degrees/Fan 160 degrees/Gas 4. Put muffin cases into a 12-hole muffin tin.
Add the butter and sugar to a mixing bowl and then mix until incorporated. Then add the eggs and mix in. Once the eggs are incorporated, add the flour and fold in until incorporated then add the milk. Mix until incorporated. .
Using an ice cream scoop, scoop the mixture into the cases. Bake in the pre-heated oven for about 20-25 minutes until risen and golden brown. Lift paper cases out of the tin and cool cakes on a wire rack until completely cold before icing.
Once the cupcakes are cooled, using a cupcake corer and core out the middle of each cupcake then fill the centres with a small amount of strawberry jam, using a small bit of the cupcake that cored out, put back on top of the jam.