Preheat oven to 350º.
Line an 8 x 8 inch baking pan with non-stick foil.
Microwave butter and chocolate until melted. Cool.
Add sugar into chocolate till combined.
Whisk in eggs one at a time, then vanilla.
Fold in flour and salt. Stir in reeses and pour into pan.
Sprinkle extras on top.
Bake 40-45 minutes.