Ingredients:

1 c. Margarine

1 c. Sugar

2 Tbsp. Water

1 Tbsp. Light corn syrup

1 tsp. Vanilla

2 1/2 c. Freshly-popped popcorn

Procedure:

Melt margarine over low heat in a heavy saucepan

Remove from heat, stir in sugar

Put back over low heat until mixture comes to a full boil, stirring constantly.

Stir in water and corn syrup.

Cook, stirring occasionally, to soft crack stage 
( 270 degrees F on a candy thermometer)

Remove from heat, stir in vanilla then popcorn.  Mix lightly.

Spread quickly in buttered 15x10x1 sheet pan.  Press down with spatula.

Cool until firm.  Then break into large irregular pieces (like peanut brittle).

Store in airtight containers.