For the buttermilk cake, preheat the oven to 180 °C top/bottom heat or 160 °C convection oven. Line a loaf pan with baking paper. Mix all ingredients for the cake in a bowl and pour into pan.
Bake on middle rack for about 1 hour until golden brown. Let cool well before glazing and remove from pan. Meanwhile, toast the almonds in a pan without fat over medium heat until golden brown and let cool.
Melt couverture with 1 tablespoon canola oil in a hot water bath over low heat. Glaze cake with couverture and sprinkle with almonds.