Skillet Chocolate Fudge

In a large, heavy bottomed frying pan, mix sugar and half-and-half. Bring
to boil over low heat, then add corn syrup and stir gently a few times.
Insert candy thermometer and cook, without stirring, until it registers
between 236 and 238 degrees. (On humid or rainy days, or if your kitchen is
humid, cook to the higher temperature.) Do not remove thermometer. Remove
frying pan from heat and allow to cool; sprinkle chocolate pieces over hot
syrup and add chunk of butter, but DO NOT STIR. Do not move or agitate
syrup in any way. Allow chocolate and butter to melt. When syrup has cooled
to 110 degrees on candy thermometer, remove thermometer. Spoon and scrape
contents of pan into bowl of electric mixer. Add vanilla and salt and turn
mixer on to low speed. Beat until candy begins to harden. Immediately
scrape and spoon candy out of mixing bowl onto flat surface;it will still
be warm. With both hands, knead candy hard for a moment, then knead in
pecans. Line an 8×8-inch square pan with plastic wrap. Press fudge firmly
into pan, flattening it on top, and pressing it into corners. Cover tightly
and let sit for about 6 to 8 hours or overnight. Remove fudge from square
pan with aid of plastic wrap. With a sharp knife, cut fudge into 8
lengthwise rows. Then make 6 more rows at right angles to first cuts.
*Note: if peppermint fudge is desired, omit vanilla and substitute 1/4
teaspoon peppermint extract or to taste.