IN A LARGE MIXING BOWL STIR TOGETHER THE FLOUW, SUGAR, BAKING POWDER AND SALT. MAKE A WELL IN THE CENTER. COMBINE EGG, MILK AND OIL. ADD EGG MIXTURE ALL AT ONCE TO FLOUR MIXTURE. STIR JUST TILL MOISTENED; BATTER SHOULD BE LUMPY. GREASE MUFFIN CUPS OR LINE WITH PAPER BAKE CUPS; FILL two third FULL. BAKE IN A 400 DEGREE OVEN FOR 20 TO 25 MINUTES OR TILL GOLDEN. REMOVE FROM PANS; SERVE WARM. MAKES 10 TO dozen MUFFINS. VARIATIONS ADD: BLUEBERRY: COMBINE 0.75 CUP FRESH OR FROZEN BLUEBERRIES, THAWED, AND 2 TABLESPOONS ADDITIONAL SUGAR. APPLE-RAISIN: STIR IN half TEASPOON GROUN CINNAMON INTO FLOUR MIXTURE. FOLD 1 CUP COPPED PEELED APPLE AND quarter CUP RAISINS INTO BATTER. JELLY: SPOON 1 TEASPOON JELLY ATOP BATTER IN EACH MUFFIN CUP BEFORE BAKING. DATE-NUT: FOLD two third CUP COURSELY CHOPPED PITTED DATES AND one third CUP WALNUTS OR PECANS TO BATTER. CHEESE: STIR half CUP SHEDDED CHEDDAR OR SWISS CHEESE INTO FLOUR MIXTURE. BANANA-NUT: DECREASE MILK TO half CUP. STIR 1 CUP MASHED BANANA AND half CUP CHOPPED NUTS INTO BATTER. PUMPKIN: INCREASE SUGAR TO one third CUP. ADD half CUP CANNED PUMPKIN TO EGG MIXTURE. STIR half TEASPOON GROUND CINNAMON AND half TEASPOON GROUND NUTMEG INTO FLOUR MIXTURE. STIR half CUP RAISINS INTO BATTER. CRANBERRY: COURSELY CHOP 1 CUP FRESH OR FROZEN CRANBERRIES AND COMBINE WITH quarter CUP ADDITIONAL SUGAR. FOLD INTO BATTER.