Preheat a skillet to medium-high heat.
Butter 4 slices of bread. Turn slices over and spread the non-buttered side of all 4 slices with apricot preserves. Set aside.
Butter one side of the 4 remaining slices of bread. Lay each of the 4 butter-only slices, buttered side down, onto the skillet. Add 2 slices Cooper Cheese, crisscrossed to make an X on each sandwich. Add a layer of spinach leaves. Top each sandwich with the remaining 4 slices of bread, apricot side down and buttered side up.
Grill sandwiches until bottom bread is golden brown, or about 2-4 minutes. Carefully flip sandwiches and grill another 2-4 minutes, or until bread is golden brown and cheese is melted. If needed, you can cover the sandwiches with a metal bowl to speed the melting process.
Remove sandwiches from heat, serve and enjoy!