With 1 strand of A and 1 strand of B held tog, cast on 40 sts. Work even in garter st for 2” [5 cm]. Change to St st (k on RS, p on WS) and work even until piece measures 5” [12.5 cm] from beg, ending with a WS row.
Next (Decrease) Row (RS) *K 6, k2tog; repeat from * across – 35 sts.
Work 3 rows even.
Next (Decrease) Row (RS) *K 2, k2tog; repeat across, ending with k 3 – 27 sts.
Work 1 row even.
Next (Decrease) Row (RS) K 1, *k2tog; repeat from * to last 2 sts, ending k 2 – 15 sts.
Cut yarn, leaving a long tail, and pull end through remaining sts. Sew up seam.
Wrap A around 6” [15 cm] piece of cardboard – the more wraps, the fuller your pompom will be. Cut a 24” [61 cm] strand of yarn, fold it in half, and lay it on a table. Carefully slide yarn off cardboard, center it over the doubled strand, and use strand to tie the middle tightly, knotting twice. Cut loops of pompom and trim to make even. Use ends of doubled strand to attach pompom to Hat.