1 1/2 cups blanched, slivered almonds, toasted and cooled
Blend the flours, salt, baking soda; add the almonds and toss to coat, set aside.
In a large mixing bowl, beat the butter until creamy, about 5 minutes. Add the sugar and beat on medium low until very creamy, about 5 minutes. Reduce the beater speed to low and add the egg and vanilla; continue to beat until well blended. Stir in the flour mixture just until well combined; do not overbeat.
Divide the batter into 3 equal pieces and equally distribute them in the bottom of zipped plastic freezer bags. Roll each section of the dough into logs. Zip the bags closed and place them in the freezer overnight, or until needed.
Preheat the oven to 350 degrees F.
Remove one log at a time from the freezer. While each log is still frozen, place it on a cutting board. Use a large sharp knife to divide each log into 24 equal pieces. Place 12 of the cookies on an ungreased Silpat sheet on top of a cookie sheet. Flatten each cold cookie slightly with the palm of your hand. When the first two dozen cookies are baked and cooling, you may remove another roll from the freezer and start on it. (The cookies hold together better, cook more evenly, and develop a better texture if they are placed in the oven while they are still frozen.)
Bake one sheet at a time for about 10 minutes, or until the cookies have turned golden brown at the edges. Rotate the cookie sheets from front to back after 5 minutes. Cool completely on racks.