These are a lot of work, but they're so delicious, and so pretty, that they're definitely worth it. You need a pastry bag with a #2 star tip to make 'em. I only make one batch a year to put in Christmas cookie baskets.
Soften butter. With electric mixer at medium speed, beat butter, brown sugar, and sour cream until light and fluffy.
At low speed, beat in flour. Remove from mixer and stir in nuts.
Divide dough in half. Shape each half into a roll about 1-1/2" in diameter. Wrap in plastic wrap and refrigerate overnight.
Preheat oven to 350. Cut rolls into 1/4" slices and place on ungreased cookie sheets.
Beat egg whites slightly with electric mixer. Crumble almond paste into egg whites, beating until added. Add sugar two tablespoons at a time, beating until well blended. Place mixture in a pastry bag with a #2 star tip and pipe a circle around the edge of each cookie (to form a wreath shape).
Bake 12-15 minutes, or until light brown.
When cooled, fill center of wreaths with cherry preserves.