Foundation pieced and appliqued.
Print or trace the block diagram onto foundation paper and extend the lines as in the photo.
Number and cut out as below.
Foundation piece the two sections and trim the seam allowances to 1/4".
Sew the sections together.
Applique the center shape onto the block.
I used the "freezer paper on top" method:
Trace or print the center shape onto the dull side of freezer paper and cut out.
Using a warm, dry iron, iron the shape onto the right side of your background fabric and cut out, leaving a 1/4" seam allowance all around. Clip the inside corners.
Baste this in place on the block.
Applique, turning the seam allowances under as you go.