An easy one!
Cut a rectangle 2.75"x5.5" out of each of your two fabrics. Sew them together along the long edge. Press.
Cut the resulting rectangle in half. You will now have two blocks, 2.75"x5"
Attach them along the long edges again, but turn one rectangle 180 degrees as in the picture. You now have your square block.
Using your favorite applique technique, trace and applique the two melons in position on the block.
How easy was that?