Preheat the oven to 350 degrees and line a 9x13 baking sheet with parchment paper.
Cut the butter into evenly sized pieces and place in a saucepan over medium-high heat.
Stir frequently and keep a close eye on the butter as it gets foamy. As soon as you smell the rich and nutty scent, remove the saucepan from the heat and set aside.
Combine the cream cheese and sugar for the cheesecake portion in a bowl and beat on medium speed until smooth. Add in the egg and vanilla, mixing until incorporated. Set aside.
Now that the butter has cooled slightly, transfer it to a large heatproof bowl. Add the brown sugar and whisk until fully incorporated, then whisk in the eggs, vanilla, salt, cardamom and flour.
Set about ¼ of the blondie base mixture aside and press the remaining ¾ of the mixture into an even layer in the prepared baking dish.
Spread the cheesecake layer on top and then drop small dollops of the cherry jam on top of the cheesecake.
Crumble the remaining blondie mixture and drop in dollops on top of the cherry cheesecake mixture.
Bake for 50-60 minutes or until the set. A toothpick inserted in the center will come out clean.
Let cool to room temperature before refrigerating for a few hours. Slice into 16 squares.
Notes
Refrigeration is optional, but the blondies stay together better once the mixture has chilled and it is easier to cut.