Place both types sugar and the cream in a heavy saucepan and bring to a boil over medium heat, stirring constantly. When the temperature reaches 228 degrees on candy thermometer, stir in the butter and pecans and continue to cook, stirring constantly, until the mixture reaches 236 degrees. Remove the pan from the heat and allow the mixture to cool for 5 minutes. Beat the mixture with a wooden spoon until the candy coats the pecans but does not lose its gloss. Drop the pralines 1 tablespoon at a time onto a well-greased piece of aluminum foil or a slab of confectioner's marble. Allow the pralines to cool. They can be eaten as is, stored in tins, or crumbled over vanilla ice cream for a New Orleans--style dessert.
Recipe courtesy of Jessica Harris, "The Welcome Table"