This one is a little tricky, but it’s good practice. I wondered if extra tall Xs would work. I think they look good!
Key: Red indicates U3. Pink indicates Under. Blue indicates Over. Purple indicates X Stitch.
R6: P9, perform X Stitch over 4 rows (instead of 3). After completing X stitch, P19 (which includes the P3 across the top of the first X). Perform X stitch. P9 (which includes the P3 across the top of the second X).
R9: Perform X Stitch according to instructions in earlier blog post.
R11 & 13: Rpt R6 & 8
Note: You may also choose to P across the bottom of the Xs. Then they won’t show on the back of the square.