Preheat the oven 350°F.
Whisk together the all-purpose flour, whole wheat flour, oat bran, baking soda, cinnamon, cloves, ginger and salt in a medium bowl.
In a large bowl with an electric mixer on medium-high speed, beat together the sugar, oil, molasses and egg until well-blended. Stir in the flour mixture and mix well.
Shape into 1-inch balls, roll them gently in sugar and place the balls 2 inches apart on an ungreased baking sheet. Use the bottom of a drinking glass to gently flatten the cookies.
Bake for 10 minutes. Transfer the baking sheet to a rack to cool for 5 minutes. Transfer the cookies to the rack to cool completely.
To make big, soft molasses cookies: Substitute 3/4 cup (1 1/2 sticks) softened butter for the oil. Beat the sugar and butter until light and fluffy then add the molasses and egg, and beat until blended. Roll the dough into 2-inch balls, place 2 1/2 inches apart on the baking sheet, and bake 11-12 minutes. (This makes 24 big cookies.)