The heart only waffles, usually 5 of them in the iron, are a traditional scandinavian dessert. They irons are still made today and readily available. The easiest ones to use are the electric, teflon coated ones, Villaware, Cuisinart and others. If I wanted a reasonably priced, quality cast iron one I would get one made by Jotul, nearly always available on eBay, just search for Jotul (they don't make them anymore, but were made into the 1970s). Sell for $20 to $40 and are worth it. These irons have a very short base, like 3/4" high, or can be placed directly on the stove. The base was optional.
I'll look in the recipe area at what's posted. I have one for these that is mainly butter and heavy cream with a touch of flour to hold it together. They are crisp, light, tasty, and a cholesterol nightmare.
tom