You COULD take a pattern for a felted hat and make it without felting it: you'd have to use much smaller needles. What i would do is start with a needle sized 2 smaller than recommended, and knit a swatch, and measure your guage... then, check out the pattern... if it says to cast on 50stitches, will 50 stitches in your guage give you enough inches to fit around your head? If your guage tells you that the hat would still be too big, then try smaller needles. I think doing this would require a lot of trial and error AND a lot of math. Fortunately i am a math nerd, so i can probablly help with that. But start with a guage swatch, and go from there.