Preheat the oven to 180C (160CFan) and line a 9 inch square cake tin with baking parchment. Leave to one side.
In a bowl cream together the butter and both sugars until lovely and light in colour.
Add in the eggs, plain flour, vanilla extract and white chocolate and mix again.
Pour half of the mixture into your cake tin and smooth until flat and even.
Randomly add spoonfuls of the caramel over the top of the mixture. Remember and keep some for the top.
Add the remaining blondie mixture on top and again add some caramel.
Using skewer or a knife swirl the caramel through the blondie mixture.
Bake in the oven for 25-30 minutes, until they are golden in colour and ever so slightly wobble.
Remove from the oven and leave to cool in the tin for 15-20 minutes before transferring to a wire rack to cool fully.