Easter Sugar Cookies

To prepare cookies: Whisk all-purpose flour, whole-wheat flour, baking powder and salt in a large bowl. Beat butter, oil and granulated sugar in a medium bowl with an electric mixer on medium speed until very light and fluffy, about 2 minutes. Beat in egg and vanilla until smooth. Gradually beat the dry ingredients into the wet ingredients to form a smooth, slightly stiff dough. If the dough is too stiff, add water, 1 tablespoon at a time.

Divide the dough in half and shape into flat disks. Place each between large sheets of parchment paper. Roll out to 1/4-inch thick. Stack the dough pieces with their parchment on a baking sheet. Refrigerate until cold, about 30 minutes, or freeze for about 15 minutes.

Preheat oven to 350 degrees F. Line several large baking sheets with parchment paper.

Working with one piece of dough at a time, gently peel away the bottom sheet of parchment, then pat it back into place. (This will make it easier to lift cookies off later.) Remove the top sheet and cut out cookies with 2 1/2- to 3-inch cookie cutters. Transfer the cookies to the prepared pans, spacing them about 1 1/2 inches apart. Reroll any dough scraps and continue cutting out cookies until all the dough is used. (If at any point the dough softens too much to handle easily, refrigerate until firm again.)

Bake the cookies, one pan at a time, until golden at the edges, 9 to 12 minutes. Transfer the pan to a wire rack and let cool for 2 minutes, then transfer the cookies to the rack to cool completely.

To prepare icing: Whisk confectioners' sugar and meringue powder (or egg white powder) in a medium bowl. Whisk in 1/4 cup warm water. Divide the icing equally among 3 bowls. Add one powder to each bowl, stirring until evenly blended. If necessary, stir in more confectioners' sugar or water to achieve your preferred consistency. Ice the cookies as desired.