Toastnet

A net, for those of you who are interested, is a flat shape that can be folded up to make a polyhedron. For instance, a large equilateral triangle, divided into four smaller equilateral triangles, is a net of the tetrahedron. Likewise, six squares arranged in a cross is a net of the cube.

So, toast. The idea is very simple. The toastnet device is basically a cookie-cutter, but in addition it has blades which are blunt and not quite flush with the other edges. When pressed firmly onto a piece of toast, it cuts out the net of a cube (or tetrahedron, or other polyhedron of your choice), and also makes creases for the fold-lines.

Once cut in this way, the toast can be folded to make a perfect cube or other shape, within which can be placed a healthy dollop of butter and a spoonful of jam before the final flap is closed.