I've been pleased with the King Arthur Flour chocolate pizzelle recipe,
I make it pretty much as-is, though I drop the butter down to 85g.
Trying to change things around I've made variations on the flavors. I've made strawberry pizzelles using freeze-dried strawberries, blended into a powder and substituted for the cocoa powder in the same amount (21g) and it turned out nicely. Oddly, I also tried it with freeze-dried raspberries, but they didn't taste very raspberryish.
By happenstance the bags of freeze-dried berries are exactly 42 grams, so I have another 21g of raspberry to use, but I want the berry taste to be stronger. My thought had been to substitute some raspberry jam for some of the sugar (198g/1 cup). I'm not worried about reducing sweetness but about consistency. Can I get away with about 1/4 cup of raspberry jam in place of 1/4 cup sugar? 1/3 to 1/3 cup? Or would the ratios be different because of their different consistencies?