Mix the buttermilk, oil and egg. Sift all the dry ingredients on the top, mix quickly. Pour hot coffee into the dough and stir. Put the dough in the baking pan, with a diameter of 20 cm and bake in the oven preheated up to 180C for about 35-40 minutes until a dry toothpick. Cool, cut the «hump», if it is formed and cut the cake into 2 equal parts.