Preheat the oven to 350 degrees F. Spray the tart shells with cooking spray and set aside.
For the crust: Place the hazelnuts, granulated sugar and graham crackers in a food processor and pulse until it looks like cornmeal. Add the butter, a little at a time, pulsing until the mixture comes together. Divide among the tart shells and press up the sides, making sure the crust is tightly packed.
For the filling: In a large bowl, mix together the brown sugar, vanilla bean paste, salt and eggs. Add the bacon grease and maple syrup; mix to combine. Stir in the hazelnuts and pecans.
Sprinkle the hazelnuts and pecans onto the bottoms of the crusts. Pour the syrup mixture over the nuts. Sprinkle the tops with bacon. Bake until set, about 25 minutes. Let cool.
For the mousse: In the bowl of a stand mixer fitted with the whip attachment, whip the cream cheese for 30 seconds to aerate it. Add the cream, confectioners' sugar, cocoa powder, bourbon, vanilla bean paste and salt and whip until light and fluffy. Taste and add more cocoa powder if desired.
Pop the cooled tarts out of the pan and place on individual plates. Spoon the mousse into small dishes, garnish with chocolate curls and mint leaves, and serve on the side.
If serving mousse on top of tarts, there will be extra mousse left over.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.