Put the cream into a small pan, and heat gently to simmering point. Remove from the heat and break the chocolate into the pan. When the chocolate has melted, stir until smooth. Cool then refrigerate about 1 hour, stirring occasionally until the mixture is thick.
Heat the oven 180C/160Cfan/350F/gas 4. Place muffin paper cases into one or two muffin tins. In a large bowl beat the cake mix with the oil, eggs and 250ml water on low speed for 30 seconds, then on medium speed for 2 minutes.
Spoon the cake mixture into the paper cases to fill by 2/3rds. Add a rounded teaspoon of the cold chocolate mixture to the middle of each cupcake.
Bake 15-20 minutes or until the top springs back when lightly touched. Cool 2 minutes before transferring to a rack to cool. Spread with frosting and just before serving, dust with a little icing sugar.
TIP: Serve with a few halved strawberries if liked. If you only have one 12 hole muffin tin, cover and refrigerate the rest of the cake mix while baking the first batch.