Preheat your oven to 450 degrees F (232 C).
In a large bowl, mix together the flour, sugar, baking powder, and salt. Cut in the shortening until it resembles small pea-sized pieces.
Make a well in the center of the mixture and slowly pour in the buttermilk while stirring. Mix until the dough is soft and pliable, but not too sticky.
Dust your work surface with some of the remaining flour and turn out the dough onto it. Knead a few times and then roll out to around 1/2-inch thick. Cut into desired biscuit shapes using either a biscuit cutter or a sharp knife.
Place the biscuits on a baking sheet lined with parchment paper and brush them with melted butter. Sprinkle the brown sugar over each biscuit and bake for about 15 minutes or until golden brown.
Remove the biscuits from the oven and let them cool for a few minutes before serving. Enjoy your homemade Hardee's Biscuits!