New Orleans Style Pralines

1 1/2 cups sugar
1 1/2 cups firmly packed brown sugar
1 cup evaporated milk
1/4 cup butter or margarine
2 cups pecan halves
1 tsp. vanilla extract

Butter a large piece of waxed paper and put aside.  Combine sugars and milk in large pan.  Bring to a boil, stirring occasionally.  Cook over medium heat, stirring frequently, until mixture reaches 228 degrees.  Add butter and pecans and continue cooking, stirring constantly, until mixture reaches soft ball stage (236 degrees).  Remove from heat and stir in vanilla.  Beat vigorously with a wooden spoon until mixture just begins to thicken.  Working rapidly, drop by rounded tablespoons onto greased waxed paper.  Let stand until firm.  Makes 3 dozen pralines.