Preheat the oven to 350ºF.
Grease a mini muffin tin and set aside.
In a large bowl, cream together the melted butter and sugar.
Add in the egg, mixing until well combined.
Add in the flour and baking powder.
Add in the milk and mix everything until well combined.
Fold in the diced strawberries and mini chocolate chips until just combined.
Fill the muffin tin with batter, dividing it evenly amongst the 24 cups. (Cups will be full)
Bake for 14-16 minutes.
Let cool before serving.