With smaller needles and A, cast on 29 (37) sts.
Row 1 (WS) P 1, (k 1, p 1) across.
Row 2 K 1, (p 1, k 1) across.
Repeat these 2 rows for 3 (3½)" [7.5 (9) cm], ending with a WS row. Change to larger needles and work 8 (10) rows in St st.
Row 1 (RS) K 14 (18), place marker, M1, k 1, M1, place marker, k 14 (18).
Row 2 and All WS Rows Purl.
Row 3 K to marker, slip marker, M1, k to next marker, M1, slip marker, k to end.
Repeat Rows 2-3 until there are 11 (15) sts between markers, ending with a WS row. K 14 (18), remove marker, place next 11 (15) sts on holder, cast on 1 st, k 14 (18) sts – 29 (37) sts.
Work even in St st until piece measures 9 (10)" [23 (25.5) cm] from beginning, ending with a RS row. P 14 (18), place marker, p 1, place marker, p 14 (18).
Row 1 (RS) K 1, ssk, k to 2 sts before marker, k2tog, slip marker, k 1, slip marker, ssk, k to last 3 sts, k2tog, k 1.
Row 2 Purl.
Repeat these 2 rows 2 (3) more times, then repeat Row 1 once more – 13 (17) sts.
Next Row P 6 (8), p2tog, p to end of row – 12 (16) sts.
Last Row K2tog across – 6 (8) sts.
Break yarn, leaving a 24 inches [61 cm] tail. Using large-eyed, blunt needle, thread tail though remaining sts; pull tightly and secure. Do not trim tail.
Slip 11 (15) sts from holder onto larger needles. Join A and work 7 (9) rows in St st, ending with a RS row.
Last Row P2tog across, ending p 1 – 6 (8) sts.
Break yarn, leaving an 8 inches [20.5 cm] tail. Using large-eyed, blunt needle, thread tail through remaining sts; pull tightly and secure. Do not trim tail.
Heart Trim With larger needles and B, cast on 30 (32) sts. Bind off all sts. Position trim in the shape of a heart on back of Mitten and sew in place.
Using tails, sew cuff, palm and thumb seams, taking care to close opening at base of thumb. Weave in ends.
Twisted Cord Cut 2 strands of A, each 8 (9) yards [7.5 (8.5) meters] long; fold in half. Secure folded ends around door knob. Twist other end until taught and yarn begins to kink. Release end from door knob. Bring ends together and let cord twist on itself, smoothing to even the twist. Knot ends. Attach ends to inside cuff seam of each Mitten.