Peel and chop the garlic. Halve the avocado, remove the stone, peel the skin off the flesh. Dice the flesh. Puree avocado, garlic, lime juice and oil with a blender.
Stir in the créme fraiche. Season with salt, pepper, sugar and chilli powder. Roast the toast bread in a toaster. Spread one side of the toast bread slices evenly with avocado cream. Cover 5 slices of toast bread with ham.
Place the remaining slices of toast on top and press down lightly. Quarter diagonally. Arrange sandwich breads on plates.