Microwave Pecan Brittle

I made this as Christmas gifts last year and had many requests for the recipe. This stuff is GOOD.

1 cup white sugar
1/2 cup light corn syrup
1/4 tsp. salt
1 1/2 cups pecan pieces (chopped chunky)
1 tsp. vanilla (Mexican vanilla is the best)
1 TBS butter
1 1/2 tsp. baking soda

Butter a (rimmed) cookie sheet well. Combine sugar, corn syrup, and salt in glass pyrex or other microwave safe bowl. Do not use plastic. Cook 4 minutes on high. Add pecans, stir well and cook 4 more minutes. Add vanilla and butter. Stir well and cook 2 more minutes. Remove from microwave and add soda. Stir well but quickly, only 8-10 stirs to get soda mixed in. Mixture will start to foam up when soda hits it. Immediately pour out onto buttered cookie sheet and scrape all out at once. Quickly pick up cookie sheet and spread the mixture out by leaning the sheet to and fro. (Act fast because this stuff starts to harden very fast.) DO NOT spread with a knife or any other utensil. Let it cook completely. Turn out the hardened piece onto wax paper. Wipe off extra butter from it so it won't be greasy. Break into pieces by whacking it with the handle end of a table knife.