You will need a 23cm x 30cm rectangular non-stick baking tin.
Preheat an oven to 180oC (fan 160oC) Gas mark 4.
Grease and line the baking tin with baking parchment or silicone paper.
Gently melt half of the white chocolate with butter in a bowl over a saucepan of simmering water. Set aside and cool slightly.
In a separate bowl, beat the eggs and sugar together.
Add the melted chocolate and butter to the egg mixture and whisk well.
Sift the flour, then use a spatula to fold into the mixture. Stir in strawberries.
Pour the mixture into a prepared baking tin.
Scatter the remaining white chocolate over the mixture, place it into a hot oven and bake for 45 - 50 minutes.
Cool for 5 minutes in the baking tray, turn out onto a cooling rack, remove the baking parchment, and cool completely before cutting into slices and storing in an airtight container.