No formal pattern, but it shouldn't be hard to wing it.
Just find a turtleneck sweater pattern. Take the number of stitches/needle size from the pattern and knit [using dpn] however many inches you want for the neck portion.
Then divide the number of stitches in half. Add a few stitches to the front and be sure to deduct those stitches from the back - then put the front portion of stitches on straight needles, cast on enough stitches at either edge to be hidden under the shoulder. Now knit away for the front flap of the "dicky" [or, if you want to be more formal, "richard"
Do the same for the smaller number of back stitches - casting on the same number at each edge to fit beneath the shoulders. Knit away for the back flap, which is usually shorter than the front flap.
Hint: if you make the flaps stockingette stitch, it's a good idea to maintain a border of, say, 5 sts in garter stitch. Then block when you're done.