Line a 9x13 baking pan with parchment paper or grease and flour to prevent sticking.
In a small saucepan, melt butter over medium-low heat.
Add in brown sugar. Stir and cook for 1 minute.
Remove and allow the butter-sugar mixture to sit for a few minutes to cool.
Slowly whisk in eggs and vanilla extract.
Stir in flour and chopped pecans.
Pour Charleston Chewies batter into the prepared baking pan and bake for 25-30 minutes. Edges should be set but middle may still be slightly soft. Oven temperatures vary so watch closely.
Allow to cool. Dust with confectioner's sugar. Cut into squares. Enjoy!