Pre heat your oven to 160C Fan/180C/350F/Gas Mark 4, and grease and line a 12" x 9" traybake tin
Melt the butter with the golden caster sugar in a pan on a low heat
Once the butter has melted, take the pan off the heat and add the white chocolate. Leave it for a couple of minutes to melt, then stir together. Leave the mixture to cool for 5 minutes
Break the eggs into a bowl and add them to the mixture, keep whisking as you pour them in to make sure the mixture doesn't cook the eggs. Then stir in the vanilla extract
Add the flour and whisk it in, then pour the batter into the lined traybake tin
Place the Jammie Dodger biscuits in rows on top of the batter, then added blobs of strawberry jam all around the biscuits, once you are happy with the amount of jam, swirl it around gently using a butter knife
Bake the blondies for 30 minutes until they are golden brown all over. Leave them to cool completely in the tin before removing and slicing into pieces.