Using a hand mixer on medium speed, beat the butter and Swerve until pale yellow and fluffy. Add the bourbon, vanilla extract, and pecans and stir until well combined. Place in the refrigerator for 30 minutes, until chilled and easier to shape.
Place the chocolate chips and oil in a small microwavable safe bowl. Microwave in 30-second increments, stirring after each increment, until melted and smooth.
Have on hand 12 foil candy cups or line a tray with parchment paper. Take the pecan mixture out of the refrigerator and roll 1- tablespoon scoops (Brenda used a 1 tbsp cookie scoop that was greased to make this easier). Roll into 1 inch balls. Using a fork, dip each ball into melted chocolate to coat and tap off excess chocolate, then place in the candy cups or on the lined tray. Top each ball with a pecan half.
Place back in the refrigerator for at least 1 hour before serving. Allow balls to sit out for 10 minutes to soften before eating. Store in an airtight container in the refrigerator for up to 2 weeks.