By user-198966, member
Posted: November 28th, 2012
Whisk the flour, baking powder, and salt in a medium bowl until combined.
In a stand mixer fitted with the paddle attachment (or in a large mixing bowl with a hand-held electric mixer), beat the butter and sugar on medium speed until light and fluffy, 3 to 4 minutes. Scrape down the bowl and beater with a rubber spatula as needed. Add the egg and vanilla and continue to mix until well blended, about 1 minute. Add the flour mixture and mix on low speed until well blended, about 1 minute more.
Using a rubber spatula, gently fold in the toffee bits.
Position racks in the upper and lower thirds of the oven and heat the oven to 350 degrees F. Line 2 or more cookie sheets (preferably flat sheets with one raised edge) with parchment or nonstick baking liners.
Using a 1-Tbs. ice cream scoop (or 2 tablespoons), drop rounded balls of the dough about 1-1/2 inches apart on the prepared sheets. (At this point, you can refrigerate the cookies, covered, overnight, or freeze until firm on the sheets and then transfer to zip-top freezer bags and freeze for up to 3 months. Thaw in the refrigerator overnight before proceeding.) Dip the tops of each dough ball in sanding sugar, and return the cookies to the sheets.
Bake two sheets at a time, rotating and switching their positions halfway through, until the edges and bottoms of the cookies are golden, 11 to 13 minutes. Let the cookies cool on their sheets on wire racks for about 5 minutes, and then transfer them to the racks to cool completely.
In a small bowl, mix the confectioners' sugar, cream, and salt with a spoon or rubber spatula until well blended and smooth. Add lemon zest and food coloring, if using, and stir until well blended. If necessary, add more cream a drop at a time for a thin, spreadable consistency. (The glaze can be covered and refrigerated for up to 3 days. Bring to room temperature before using.)
Arrange the cooled cookies on a rack set over a large rimmed baking sheet. Dip the sides of each cookie to cover half or more of the cookie. Let excess glaze drip off and then transfer to the rack.
Alternatively, use a fork to drizzle the glaze over the cookies on the rack. Or partially fill one corner of a small, heavy-duty zip-top baggie with glaze, squeeze out the air, and seal the baggie. Cut off the corner and gently squeeze the bag to drizzle the glaze evenly over the cookies.
Decorate each cookie further with sanding sugar while the glaze is still wet, let the cookie sit for about 10 minutes, then invert the cookie to remove any excess. Let the cookies remain on the rack until the glaze sets up, about 3 hours.
Once they're set, serve the cookies or store in an airtight container for up to 3 days.