sliced almonds, processed until finely ground with 1/3 cup sugar
Adjust oven racks to middle postion, preheat oven to 375 degrees. Line two baking sheets with foil or parchment paper.
Whisk the flours, baking powder and salt together in a medium bowl and set aside.
Using an electric mixer, cream the butter and one cup of the sugar together at medium speed until light and fluffy, about 3 to 5 min.,scraping down the sides as needed. Add the egg and vanilla (and 2 tsp.lemon zest or 1/2 tsp.almond extract) and continue to beat at medium speed until combined, about 30 to 60 seconds. Add flour mixture and beat until combined, about 30 to 60 seconds more.
Place remaining 1/3 cup sugar in a shallow bowl, (with optional lemon zest or almonds.) Working with a level tablespoon of dough each time, roll the dough into balls. (If the dough is too soft refrigerate until firm.) Roll the balls in the sugar and place on baking sheet 2 1/2 inches apart. (12 cookies to a sheet).
Bake cookies, one tray at a time until edges are golden and centers are just set. (Don't overbake.).
Cool cookies onthe baking sheets for 5 minutes and serve warm or transfer to wire rack to cool completely.