In a large microwave-safe bowl, combine butter and sugar. Microwave for 30 seconds, then remove and stir with a whisk. Repeat process 2 more times. Though granules of sugar will remain, the goal is to get the mixture to a glossy finish.
Allow mixture to cool slightly, then add in eggs one at a time, whisking in between each addition. Whisk until the mixture lightens in color slightly.
Add in cocoa powder, salt, and vanilla extract. Fold in flour until just combined.
Pour mixture into prepared baking pan, using a spatula to spread the batter evenly to the edges.
In a medium size mixing bowl combine the cream cheese, granulated sugar and egg for the cream cheese swirl. Mix together until smooth and no lumps remain.
Drop big dollops of the cheesecake mixture and spoonfuls of jam on top of the brownies. Use a butter knife make big swirls, dragging up brownie batter from the bottom. Do not overswirl!
Bake for 35 minutes, testing for doneness by inserting a knife into the center of the brownies beginning at 30 minutes. You’ll know they’re done when the edge is set, but a knife inserted into the middle still comes out with a bit of brownie batter on it. It might take up to 40 minutes for them to cook through depending on your oven!