PERFECT SUGAR COOKIES

Steps:

• Sugar Cookies: Preheat oven to 350 degrees. In a bowl, whisk together flour, baking powder, salt, and baking soda. In a large bowl, beat butter and granulated sugar on medium-high speed until pale and fluffy, about 3 minutes. Add egg and vanilla; beat well to combine.
• Reduce speed to low and add half of flour mixture, followed by sour cream, then remaining flour mixture; beat just until smooth. (Dough will be stiff; you may need to finish mixing it with a wooden spoon.)
• Using a cookie scoop or a tablespoon, scoop dough (about 3 tablespoons at a time) and drop on parchment-lined baking sheets, spaced 3 to 4 inches apart.
• Bake, rotating sheets halfway through, until edges of cookies are just firm and tops are barely beginning to brown, 20 to 25 minutes. Transfer cookies to wire racks; let cool completely, then top with sanding sugar or lemon glaze and candied zest (below).
• Lemon Glaze: In a large bowl, whisk together egg white, sugar, and 1 teaspoon lemon juice until smooth. (If necessary, at up to 1 teaspoon more lemon juice to reach desired consistency. Glaze should be opaque but not so thin as to run down the edges of a cookie when dipped. If glaze runs, add more sugar; if too thick, add water, 1 teaspoon at a time. Use immediately. Makes: About 1/2 cup
• Candied Citrus: With a sharp paring knife, slice the ends off citrus. Following curve of fruit, cut away outermost peel, leaving most of white pith on. Slice peel lengthwise into 1/4-inch-wide strips.
• In a pot of boiling water, cook peel until tender, about 10 minutes. With a slotted spoon, transfer to a wire rack set over a rimmed baking sheet; spread in a single layer and let dry slightly, about 15 minutes.
• In a saucepan, bring sugar and 1 cup water to a boil over high heat, stirring until sugar is dissolved. Add peel and boil until translucent and syrup thickens, 8 to 10 minutes. With slotted spoon, transfer peel to rack, separating as needed. Let cool 1 hour. Toss with remaining 1/2 cup sugar to coat. Use immediately.