The idea of turning a favorite family recipe into a business has probably been tossed around many supper tables — and usually stays in dreamland. Not for Klara Sotonova. Four years ago, Czech-born Sotonova and her husband, Jefferson Diller, started Klara’s Gourmet Cookies in the Berkshires. Vanilla Walnut Crescents, their most popular sweets, are made from a classic Czech recipe that’s been in Klara’s family for generations. Every week, she hand-shapes thousands of the sugar-coated, buttery crescents and packs them in sturdy foil bags (2 ounces about $2.49; 8 ounces about $7.99). The powdered-sugar treats are especially popular at the holidays, she says, but people eat them year-round. Available at Savenor’s Market, 160 Charles St., 617-723-6328; Wasik’s Cheese Shop, 61 Central St., Wellesley, 781-237-0916; and Idylwilde Farms, 366 Central St., Acton, 978-263-5943.