These are a triumph. I never heard of Mazurka Bars, purportedly of Polish origin, until I read Bread Alone, a novel by Judith Hendricks. I don’t recall a recipe in the book for these bars and a quick search didn’t result in any recipe that resembled the description of a tart or shortbread bottom, a smack of tart apricot spread or filling and a luscious topping of caramelized walnuts. I finally found a local Russian bakery that sold Mazurka bars and bought one. Wow! Easy to figure out why they're so amazing. Here's my rendition of these sweet, tangy, chewy, buttery bars.