1/2 cup butter
1/3 cup brown sugar
1 teaspoon vanilla extract
1/2 cup Apple Cider Vinegar
1/2 cup milk
1 (1 ounce) square unsweetened chocolate, chopped
1 teaspoon vanilla extract
1/4 teaspoon salt
Butterfly an 8 inch square pan. Roll out parchment paper to fit circle. Place on bottom of greased 9 inch square pan. Cover with foil and use a wooden spoon to shape into a circle. Spread chocolate mixture on top of pan.
Bake at 350 degrees F for 55 minutes. Cool completely. Cut into 1/2 inch squares. Store in tightly covered container. Refrigerate for several hours or overnight.