Begin by peeling and coring the apple then cut it into quarters and grate it on the coarse side of the grater into a bowl. Then toss the grated apple around in 2 tbsp calvados and leave it aside for 10 minutes. Meanwhile, sift the flour, buckwheat flour and cinnamon into a bowl. Then in a separate bowl or jug, whisk the eggs and crème fraîche together, then gradually whisk this into the flour mixture using an electric hand whisk until you have a smooth, lump-free batter. Then stir in the apple and calvados.Before you make the pancakes put a large plate in a warm oven or a warming-drawer so that as you make them they can be kept warm, covered with some foil.To make the pancakes, melt the butter in the frying pan, then tip it into a cup. To make your first pancake, heat the pan over a medium heat until it is really hot then use 1 tbsp of the batter to make each pancake, cook until it becomes crisp at the edges and is a lovely golden colour underneath, then, using a palette knife or spatula, turn the crêpe over and cook the other side until crisp and golden (this should take about 45 seconds on each side.)Remove the crêpe to a warm plate. Use a wodge of kitchen paper to lubricate the pan again with melted butter, then continue cooking the pancakes until the batter is all used up. When you are ready to serve the pancakes, transfer them to warmed serving plates, giving each person three or four, lightly dusted with caster sugar. Then combine the cream and calvados, put a little on each serving and hand the rest round separately. For a special occasion you could flame these by leaving them piled on a large plate, dusting with caster sugar, then warming 3 tbsp of calvados in a small pan - light it with a match and pour the flaming calvados over the pancakes. When the flame has died down serve each person three or four pancakes with pouring cream, served separately.
