This little hat is SO adorable! I love the brim and the button band together - it is such a perfect hat for a little boy - or, attach a flower and it's great for girls, too! I also love that the brim can be worked right into the main piece, without having to fasten off, weave in ends, and then attach a new section. Way less ends to weave in this way!
This pattern is written for a baby under a year old, but you can easily adjust your hook/yarn weight for a different size. Or just add/subtract increase rows!
Here's the pattern:
150 yards worsted weight yarn (I used Vanna's Choice)
H (5.00mm) crochet hook
Sewing needle (for sewing on buttons)
1. Stitch counts are in brackets. The ch-2 at the beginning of each round counts as 1 stitch.
2. Do not work in the last stitch of each round (where the ch2 was started). This may mean that you end in the middle of a pattern (for example, you might end on a "2dc in next") - that's okay, as long as you match up with the stitch count.
1. 6 sc into ring, sl st to first sc. 
2. Ch 2, dc in same, 2dc in each stitch around. Sl st to first dc. 
3. Ch 2, dc in same, 2dc in each stitch around. Sl st to first dc. 
4. Ch 2, dc in same, dc in next. (2dc in next, dc in next) around. Sl st to first dc. 
5. Ch 2, dc in same, dc in next 2. (2dc in next, dc in next 2) around. Sl st to first dc. 
6. Ch 2, dc in same, dc in next 4. (2dc in next, dc in next 4) around. Sl st to first dc. 
7-12: Ch 2, dc in each stitch around. Sl st to first dc. 
13: (front loops only) Ch 2, dc in next 19. 2sc down side of brim, (now both loops again) sc in each stitch around. 2sc up side of brim, sc in next 19. Sl st in next.
Fasten off, weave in ends.
1. Ch 20. Sc in second chain from hook and each across, working in the horizontal bar underneath the two top loops of the chain stitches.
2. Ch 1, turn. Sc in each stitch across.
Sew buttons onto the band, sew the band onto the hat, and you're done!
As with all my other patterns, feel free to make/donate as many of these hats as you like, I just ask that if you sell the finished product online, you credit my blog. Thanks!
Enjoy, and I would love to see pictures of the hat if you make one!