Spread chopped pecans and pecan halves in a single layer on a baking sheet. Toast in a preheated 350°F for 6-8 minutes. Set aside to cool.
Crush pecan shortbread cookies using a food processor until fine crumbs. Add to a mixing bowl with chopped pecans and powdered sugar. Mix together.
In a separate bowl or large measuring cup, whisk together Kentucky Bourbon, butter, corn syrup and vanilla extract until fully combined. Pour into crumbs and mix until fully moistened.
Transfer to an airtight container and chill for 4 hours or overnight to set.
Bourbon Balls Mixture: Remove from fridge. Roll into 1-inch balls. (Similar to a meatball.) Place onto a parchment lined sheet pan and keep chilled, or pop into the freezer, while working in batches to coat.
Chocolate: Melt chocolate with vegetable shortening in a double boiler over gently simmering water until stirring until smooth.
Use two forks or a toothpick to dip the balls into the chocolate to coat. Place onto a sheet pan lined with parchment or wax paper. Immediately top half with a single pecan and sprinkle the tops of the remaining bourbon balls with toffee bits. Chill until set.
Powdered Sugar Coating: Pour 1 cup powdered sugar into a shallow dish or small bowl. Roll one third of bourbon balls in powdered sugar until coated on all sides.
Store chilled in an airtight container for 3-5 days before serving.
Store Bourbon Balls chilled in an airtight container in the refrigerator for up to 4 weeks.