I recently did a flannel baby quilt with this method. Didn't think I could pull off any type of binding with flannel quickly.
I layered and taped the unit from the bottom up...
batting
back - right side UP
top - right side DOWN
Pinned the 3 pieces to make sure it didn't move.
Stitch around the perimeter with the quilt top on top so I could make sure I saw the 1/4" seam part.
Leave about 12" to turn - trim close to edge then right side out.
I flattened smooth, and pinned for quilting (hand distance apart) and stitched around the binding. I sewed the closure afterwards.