Heat oven to 200 °F, grease pans.

Combine sugar, butter, syrup and salt in pot.

Stir until it bubbles around the edges.

Cook at medium still bubbling for approx. 5 minutes.

Add vanilla and baking soda.

Stir and pour immediately onto popcorn and mix.

Spread onto pans and bake for 1 hour. Stirring every 15 minutes.