Preheat the oven to 350°F (175°C).

In a bowl, mix together melted butter and sugar until well combined.

Add in the eggs and vanilla extract, mixing well after each addition.

In a separate bowl, whisk together the flour, cocoa powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fold in the fresh raspberries.

In another bowl, beat the cream cheese until smooth.

Add the sour cream, granulated sugar, egg, and vanilla extract to the cream cheese and mix until smooth and creamy.

Pour half of the brownie batter into a greased baking pan and spread it evenly.

Spoon the cheesecake mixture over the brownie batter.

Drop spoonfuls of the remaining brownie batter on top of the cheesecake layer.

Use a knife to swirl the two batters together gently.

Bake for about 50 minutes or until a toothpick inserted comes out with a few moist crumbs.

Allow to cool before cutting into squares.