Spread pecans in a single layer on a baking pan. Place into a preheated 350°F oven and toast for 6-8 minutes. Cool completely.
To assemble the pie: Preheat oven to 350°F. Spray a 9 inch deep dish pie or 10 inch tart pan with cooking spray.
Press crust, firmly onto bottom and sides of pan. Crimp or flute edges.
Separate chocolate chips, reserving 1 cup in a microwave safe bowl. Sprinkle remaining on bottom of crust along with toasted pecans.
In a microwave safe bowl, melt 1 cup chocolate chips with butter. Heat in 20 second increments stopping to stir each time. Repeat until smooth.
In a medium size mixing bowl, using an electric mixer, beat together corn syrup, brown sugar, granulated sugar, eggs, flour and vanilla until fully combined. Beat in melted chocolate.
Pour filling evenly into pie crust. Bake for 40-45 minutes or until set when gently shaken. (Filling may puff up while baking but, will settle as it cools)
Cool for 2 hours on a cooling rack.
Chocolate ganache drizzle: Melt ½ cup of dark or semi sweet chocolate chips with 3 Tbsp of heavy cream in the microwave until smooth. Heat in 20 second increments, stopping to stir each time. Repeat until smooth.
Serve warm drizzled with chocolate ganache and a scoop of vanilla ice cream.
Store leftovers in an airtight container at room temperature,