Whisk all-purpose flour, whole-wheat flour, baking powder and salt in a medium bowl.

Puree tofu in a food processor. Add egg, sugar, oil, butter and vanilla; process until smooth, stopping once or twice to scrape down the sides. Add the dry ingredients and pulse several times just until dough clumps together.

Transfer the dough to a lightly floured surface and knead several times. Divide in half and press each piece into a disk. Dust disks with flour and wrap in plastic wrap. Refrigerate for at least 2 hours or overnight.

Preheat oven to 350 degrees F. Line several baking sheets with parchment paper or coat with cooking spray.

Working with one piece at a time, on a lightly floured surface, roll the dough slightly less than 1/4-inch thick. Cut out shapes with a cookie cutter. Gather scraps and re-roll. Place cookies about 1/2-inch apart on the prepared baking sheets. If using Cinnamon-Sugar Topping, add it now.

Bake cookies, one sheet at a time, until light golden around the edges, 12 to 16 minutes. Transfer cookies to a wire rack and let cool completely.

If using Decorator Icing, decorate cookies as desired. Let stand until frosting has set, 30 to 45 minutes.

Ingredient note: Choose silken-style tofu, available in most supermarkets, rather than regular tofu for this recipe. It has a custard-like texture, which is suitable for pureeing.

Cookie-Decorating Tips

To tint icing: Place small quantities of icing in several small bowls. Add a little food coloring to each one and mix well. You will obtain the most vivid colors if you use paste food colors, which are available at craft stores and cake-decorating shops.

To make a piped design: If icing seems too stiff, thin with a few drops of water. Spoon icing into a pastry bag fitted with a fine writing tip or a paper piping cone. (To make a paper piping cone, cut a piece of parchment or wax paper into a 15x12x8-inch triangle. Starting at the short corner, wrap the triangle up along the long side to make a tight cone. Fold the tip into the cone to secure it. Spoon icing into cone, close the top of the cone and fold edges over to seal. Cut a small opening in the tip.) To outline a cookie for accent, pipe a continuous line or a series of connected dots around it.

To paint cookies: Thin icing with water until it is the consistency of heavy cream. Using a clean watercolor paintbrush, coat the tops of the cookies with icing.

To make swirls: Paint cookies with one icing color. While it is still wet, use a paper piping cone or plastic condiment bottle to drop a contrasting color onto the cookies. Draw the tip of a toothpick through both colors, creating a swirled effect.

MAKE AHEAD TIP: Store in an airtight container for up to 2 weeks.