Scoop the praline paste into a medium bowl.

Melt the chocolate in a small bowl, using a microwave at 30-second intervals, stirring between each. Stir into praline paste.

Stir in feuilletine.

Place a piece of parchment on a work surface and scrape the praline mixture into the center. Place another piece of parchment to cover and roll to under 1/8 inch thick. Place praline, still between parchment sheets, on a baking sheet and freeze for at least 4 hours, preferably overnight.

Preheat oven to 325°F. Butter an 8- or 9-inch tart pan.

Roll out crust and fit it into the tart pan. Place a piece of parchment over the crust and fill with pie weights (or uncooked rice, or beans).

Bake 20 minutes, then rotate the crust and bake 20 minutes more. Remove pie weights and parchment and bake until golden brown, about another 20 minutes.

Let cool completely.

Measure the inside of the crust, and, if possible, find a bowl or pan lid to use as a template for cutting the praline.

Use the template to cut the praline into a circle the same size as the bottom of the crust, then return to the freezer until it's time to assemble the tart.

Chop the hazelnuts into pieces about the same size as the cocoa nibs. Set aside.

In a medium saucepan over medium heat, combine sugar, butter, corn syrup, and milk. Bring to a boil and cook to 230°F. Remove from heat, stir in hazelnuts, cocoa nibs, and cocoa.

Pour the mixture unto a piece of parchment and place another piece of parchment on top. Roll as thin as possible. Remove the top piece of parchment and transfer dentelle on the parchment to a baking sheet.

Bake for 12 minutes, or until the bubbles forming on top become small and you can smell the cocoa nibs and hazelnuts.

Let cool for 2-3 minutes, then use an inverted bowl and a chef's knife to cut out a circle about 5 inches in diameter. Let cool completely and set aside.

Melt the chocolate in a medium bowl and allow to cool to room temperature (either use a double boiler or microwave in 30-second increments, stirring in between, until chocolate is completely melted.

In a medium saucepan, mix heavy cream and corn syrup over medium heat, and bring to a simmer, stirring to combine.

Add 1/3 the heavy cream mixture to the melted chocolate and stir until smooth. Repeat two more times to incorporate the remaining cream mixture.

Stir in butter.

Peel the praline from the parchment and place on the bottom of the tart crust. Pour ganache over and smooth the top. Let cool at room temperature for at least 4 hours before placing dentelle on top, offset to one side.