Grease a small cookie sheet and line it with parchment paper. Spread the pecans into a single layer on the parchment paper.
Stirring frequently, bring butter and sugar to a boil in a 3-quart stock pot over medium low heat. Once the candy is boiling, stir occasionally until the mixture reaches 290 degrees F.
Once the candy has reached the desired temperature, gently stir in the vanilla extract. Carefully pour the mixture over the pecans. Let the candy cool (undisturbed) for about 10 minutes. Sprinkle the chocolate chips over the top.
Cover with foil and let sit for 5 minutes. Remove the foil and gently spread the chocolate with an offset spatula.
Place the candy in the refrigerator for at least 2 hours.
Lift the parchment out of the pan and place the candy on a large cutting board or solid surface. Use a knife to gently break the candy into small pieces.
Store in an air-tight container in a cool, dry place.