Line a large heavy baking sheet with parchment paper or aluminum foil and grease.  Set aside. 

Combine the sugars, heavy cream, and butter in a large heavy nonstick saucepan and cook over medium-high heat, stirring, until the sugars have dissolved, about 3 minutes. Continue to cook until the mixture reaches the softball stage, 238 to 240 degrees F on a candy thermometer, 3 to 4 minutes.

Remove from the heat, add the pecans and chocolate chips, and stir vigorously until the pecans remain suspended in the mixture, about 2 minutes. Spoon onto the prepared baking sheet. Cool completely and then crumble, as needed for the Chocolate Praline Tart, or serve individually.