Add the pecan halves to a food processor. Pulse a few times, then grind on low until they reach a sandy, coarse texture. This will give about 0.75 cups when ground.

Whisk together the sweetened condensed milk, flour, and vanilla extract in a saucepan over medium heat until fully combined and the flour is incorporated.

Stir the ground pecans into the mixture and cook for 8 to 10 minutes until thickened.

Pour the mixture into a 9x9 inch dish, cover, and chill for 20 minutes until cooled.

Line a baking sheet with parchment paper.

Use a 1 tablespoon cookie scoop to portion out the pecan filling.

Dampen hands slightly to prevent sticking, then roll the pecan mixture into balls.

Refrigerate the balls for 20 minutes.

Melt the dark chocolate candy melts in microwave in 30-second intervals, stirring until smooth.

Dip each pecan ball into the melted chocolate, shaking off excess, and place on the parchment-lined sheet.

Optional: sprinkle chopped pecans on top for garnish.

Refrigerate for an additional 20 minutes until set before serving.