Quince paste or "membrillo" is a typical dessert eaten in Spain, although it is also served with toast at the breakfast table. "Membrillo" or "Dulce de Membrillo" is a sweet, very dense jelly or paste made from the fruit of the quince tree. Try it with cheese for a light dessert or breakfast.
Slice the baguette into 1/3-inch slices and lightly toast on both sides.
Spread a thin layer of cheese on each slice.
Carefully cut membrillo into slices about 1/8-inch thick and place on top of toast with cheese.