In a heavy medium saucepan combine sugar and cornstarch or flour. Stir in milk. Cook and stir over medium heat till mixture is thickened and bubbly. Cook and stir for 2 minutes more. Remove from heat. Gradually stir about 1 cup of the hot mixture into beaten eggs.

Return all of the egg mixture to the saucepan. If using egg yolks, bring to a gentle boil; if using whole eggs, cook till nearly bubbly but do not boil. Reduce heat. Stir in butter and vanilla. Pour pudding into a bowl. Cover the surface with clear plactic wrap. Chill. Do not stir.

Chocolate Pudding-Prepare as obove, except add 1/3 cup unsweetened cocoa powder to sugar. Use 2 tablespoons cornstarch or 1/4 cup all-purpose flour, 2 2/3 cups milk, and egg yolks, not whole eggs.

Tangy Vanilla Pudding-Prepare as above, except omit butter. After chilling, stir in one 8 ounce carton sour cream or plain yogurt.