The YouTube channel The Tim Traveller has covered a few (along with a bunch of other esoteric sights, I really enjoy his stuff).

Example: https://youtu.be/iXSkjw0Kytk?si=J_X-3rbCluOcXRyz

Found it! https://maps.app.goo.gl/ZjbBb3eEYxttpzvT6

Mine was similar. As a teenager I used to make sandwiches as you describe with instant coffee granules instead of sugar. The granules would dissolve into the butter to form a brown caffeinated sludge. Yummo!