Grate cheese fresh from a block on the large holes of a box grater. Let it sit at room temperature for 10 minutes.
Spread softened butter to the very edges of one side of each bread slice.
Build the sandwich: butter-side-down, mound grated cheese to the edges, top with second slice butter-side-up.
Place crisper plate in the 6-cup container, set sandwich on plate, attach PowerPod.
Press MODE until AIR FRY illuminates. Set 375°F for 9 minutes. Press START.
At 5 minutes remaining, lift PowerPod, flip the sandwich, and rotate 90 degrees so the previously-under-fan spot moves to the edge. Replace PowerPod, press START.
When the cycle ends, rest the sandwich on a cutting board for 60 seconds, then slice diagonally and serve.