In a small saucepan set over medium-high heat, combine 3/4 cup blueberries, sugar, vinegar, cornstarch and cinnamon; bring to a boil. Reduce heat to medium and cook for 5 to 8 minutes or until thickened. Fold in remaining blueberries. Let cool completely.

Preheat oven to 350˚F. Grease 9-inch square baking pan with butter. Line bottom and sides of pan with enough parchment paper to overhang edges. Using electric mixer, beat cream cheese with sugar until light and fluffy; beat in egg. Add cream and vanilla and beat until well combined; set aside.

In a heatproof bowl set over larger pot of barely simmering water, melt butter and chocolate, stirring occasionally. Remove from heat. Stir in sugar, cocoa powder and salt. Let cool slightly. Stir in eggs, one at a time, until well combined. Stir in flour. Scrape into prepared pan; smooth top.

1. Pour Cheesecake Layer over top of the brownie batter. Drop heaping tablespoonfuls of Blueberry Compote over top; swirl with tip of knife. Bake for 40 to 45 minutes, or until only a few moist crumbs adhere to toothpick when inserted into center. Let cool completely in pan.
2. Using parchment paper, transfer to cutting board. Cover and refrigerate for at least 4 hours or overnight until firm enough to cut into squares.