Preheat oven to 250°F Fahrenheit

Melt butter in a medium sized saucepan

Add brown sugar, corn syrup, and salt

Bring mixture to a boil, stirring constantly

Remove from heat, and add baking soda and vanilla extract

Stir until smooth

Add almonds to pan and stir till all are covered

Pour sugar and almond mixture over popcorn in a large bowl

Stir until popcorn is well coated, and spread out on a large baking pan

Bake for 1 hour, stirring popcorn and almonds every 10 minutes

Remove from oven, and let cool completely

If desired, drizzle melted chocolate chips over popcorn clusters