Heat the oven to 180C/fan 160C/gas 4, then butter and line a 20cm x 30cm tin with baking paper.
Put the butter, peanut butter, sugars and white chocolate chunks in a large, wide pan. Melt gently, stirring occasionally, until the butters and chocolate have melted, and the sugar is no longer grainy. Take off the heat to cool for 5 minutes.
Stir the vanilla extract and eggs into the mixture with a wooden spoon, followed by the flour. Gently fold through 2/3 of the raspberries, and scrape everything into the prepared tin.
Dot the teaspoons of jam over the top of the mixture, then scatter over the remaining raspberries. Tip the peanuts into a sieve and shake vigorously to remove a little of the salt, then scatter them over the top, too. Bake for 30-35 minutes or until the blondie is golden and set firmly on top. Cool before cutting into chunks to serve.