See's Butterscotch Squares

2 cups brown sugar, packed
1/2 Cup brown sugar, packed (reserved for later)
3/4 cup heavy cream
6 tbsp. butter
1/4 tsp salt
1/4 tsp baking soda
1 tbl vanilla flavoring
1 1/2 cups confectioner sugar, sifted to remove clumps

Combine brown sugar, cream, butter, and salt in large heavy saucepan.
Stir to integrate. Apply medium heat, stirring constantly, until boiling.

Reduce heat to low, and simmer at a slight boil for 15 minutes,
stirring every few minutes to eliminate any boil-inhibiting skin
which might form. add 1/4 tsp baking soda before removing from the heat .
Add vanilla, confectioner’s sugar. Mix well, until sugar is
well-incorporated.add remaining brown sugar.

Pour into a square or rectangular pan such as an 8×8 or 9×9 inch,
lined with parchment paper. Let cool to room temperature
(a couple hours at least, more depending on weather).

Cut into inch-square pieces, or less.