To make the crust, mix butter, pecans, brown sugar, salt, vanilla in a medium bowl. Add flour and mix until blended. Press the dough evenly over the bottom and up the sides of a 10-inch tart pan with a removable bottom. Generously prick the bottom and sides of the crust with the tines of a fork. Bake in the lower third of an oven preheated to 350° F until the crust feels firm to the touch, about 20 to 25 minutes. Cool completely.
Once the crust is cool, prepare the cookie dough filling. Beat butter, sugars, and salt on medium speed in the bowl of a standing electric mixer until light and fluffy. Add vanilla and cream and mix well. Add flour and mix on low speed until incorporated. Stir in chocolate chips by hand.
Scrape the filling into the tart crust and spread it evenly to the edges using the back of a spoon. Smooth the top with an offset spatula as best as you can. Set aside and prepare the ganache (if not preparing ganache right away, refrigerate the filled tart crust until ready).
Place chopped chocolate in a measuring glass with a pour spout; set aside. In a small saucepan, bring cream to a boil over medium heat. Pour hot cream over the chocolate; without stirring, let the cream-chocolate mixture sit for 2 minutes. After 2 minutes, stir slowly with a rubber spatula until the mixture is smooth and glossy.
Acting quickly, pour ganache over the cookie dough filling. Carefully pick up the tart pan, tilting and rotating to spread the ganache to the tart’s edges as needed. If desired pop any large bubbles that form with a toothpick or the tip of a sharp knife.
Refrigerate uncovered until set, about 30 minutes. Serve chilled.