What the heck is a sweatshirt peplum blazer? It's the best way I could describe this jacket, which I found at H&M.
Actually, I'm not certain it was this exact blazer, but the one I saw was so lovely! It was made of sweatshirt material in bright primary red or blue, with big buttons, and princess seams. Naturally, they didn't have it in my size. I'd probably have tried to make it, even if they did... Anyway, I think this is a comparable pattern:
They each achieve a similar shape, but without the seam at the waist! And who doesn't love a nice long line?