To prepare the blood orange jam:
Peel, slice and seed the blood oranges, being sure to remove as much of the pith (white skin on fruit) as possible, as this will cause the jam to taste bitter. Puree the fruit in a blender or fruit processor until a pulpy juice forms. Pour the juice into a saucepan and whisk in the sugar, cornstarch, and vanilla. Turn the heat to medium and bring to boil, stirring occasionally. Allow to boil, stirring frequently, for 1-2 minutes until thickened slightly. Turn off the heat, skim the bubbles off the top and and place in a heat-safe container to chill in the fridge to at least room temp.
To prepare the crusts:
Preheat the oven to 350 degrees. Cream the butter in a medium-sized mixing bowl until smooth. Add the confectioner’s sugar, cinnamon, and flour and stir on low until a crumbly mixture forms. When you press it between your fingers it should pack like wet sand. Divide the mixture between the 6- 4” tart pans with removable bottoms (I used just shy of ½ cup in each pan) and press into the sides and bottom of the pan in an even layer. I find it’s easiest to press into the sides first and then smooth the remaining dough into the bottom. Place the tart pans on a rimmed baking sheet and place in the oven to pan until firm, about 13-15 minutes. Remove from oven to cool completely.
To prepare the tarts:
Combine the white chocolate and cream cheese in a microwave-safe mixing bowl and microwave in 25 second intervals, stirring regularly afterwards. This allows the white chocolate to melt gently. Continue this process until the clumps of white chocolate combine smoothly with the softened cream cheese. In a separate bowl, combine the vanilla and heavy whipping cream and whip until medium peaks form. Fold about half of the whipped cream into the cream cheese mixture and then fold the remaining whipped cream in until smooth. Be careful to not overwork it. Fill the cooled tart dishes with some of the cream cheese mixture, about 2/3 of the way full, alternating with some of the blood orange jam. I use about 2 tablespoons of sauce in each tart pan. Once the tart pans are filled, use a toothpick to gently swirl the two mixtures together. If you ended up with a big glob of cream cheese on top you can drop a few rounds of sauce on top to make pretty swirls. Place the finished tarts in the fridge to set up. Prior to eating, pull the tarts out of the fridge, pop the tarts out of the pan, and allow to rest at room temp for about 15-20 minutes to allow the crust to soften slightly. Top with toasted walnuts, if desired.