I made these into Canada/Olympic mittens for a Cabbage Patch Kid but they could be used on any soft doll in the 16" - 20" range.
I used Cascade 220 and 4.5mm needles. You could always vary the yarn weight and needle size to make the mittens bigger/smaller!
Cast on 22 stitches and join in the round. **
Knit the body of the mitten:Rounds 1-6: K1, P1 rib.
Rounds 7-8: knit
Round 9: K2, K4 onto waste yarn, knit to end with regular yarn.
Continue knitting in the round until the mitten is 3 inches from the edge of the cuff.
K1, K2tog for 2 rounds
K2tog for 1 round
Cut yarn and thread through remaining stitches, pull tight and sew the end in.
Make the thumb:
Unpick the stiches on the waste yarn and put on to two needles, picking up an extra stitch at each end of the hole (10 stitches total).
Round 1: K3, K2tog. Repeat.
Continue knitting for 5-6 rounds.
K2tog, K1 for one round.
Cut yarn and thread through remaining stitches, pull tight and sew the end in.Sew in any remaining yarn ends and knit the matching mitt!
**I used to have a hard time keeping the stitches tightly together when joining in the round until I read about this trick: Cast on an extra stitch (23 for these mitts). Divide the stitches onto three needles as normal. Without using the fourth needle knit the first stitch onto the last needle and cast off one stitch. Now you should have 22 stitches on three needles. Pick up your fourth needle and continue as usual!