Preheat the oven to 190℃ (170℃ fan)/375°F/gas mark 5. Line a muffin tin with 12 cupcake cases.
Beat 150g (5oz) sugar and 100g (3½oz) butter together until light and fluffy. Add 2 eggs one at a time beating well after each addition.
Sift 175g (6oz) plain flour, 3tablespoon cocoa powder and 2 teaspoon baking powder into the bowl and begin to fold in. When most of the flour has been incorporated add 150ml (¼pt) milk and mix well. Don't worry if the mixture looks a little curdled at this point.
Stir in 50g (2oz) plain chocolate chips then divide equally between the cupcake cases, Bake in the centre of the oven for 18-20 minutes until springy to the touch. Transfer to a wire rack to cool.
Meanwhile, melt about 75g (3oz) of the 100g (3½oz) of milk chocolate over a pan of hot water. Remove from the heat. Stir in the remaining chocolate and stir until fully melted. Dip the 12 strawberries into the chocolate to coat about half coat the strawberry in chocolate. Place on a piece of baking parchment and allow to set.
When completely cold, spoon the buttercream into a piping bag fitted with a star nozzle and pipe a swirl of buttercream on top of each cupcake. Finish with a chocolate dipped strawberry.