Preheat the oven to 180 °C (356°F).
Toast the almonds in a pan for two minutes, chop with a knife, and set aside.
In a bowl, mix the buckwheat, starch and baking powder. Set aside.
In another bowl, beat the eggs and sugar with an electric mixer for about 3-4 minutes or until the mixture is fluffy.
Add the pumpkin pulp, grated lemon zest, cinnamon, and salt to the eggs. Mix the ingredients with an electric mixer. Then, add the flours all at once and, still using the mixer, incorporate the powders into the mixture.
At last, pour in the milk and mix again with the whisk for one minute.
Now, add the almonds and mix with a spatula.
Line a baking pan with moistened, squeezed parchment paper, pour in the mixture, and bake the pumpkin cake for 40 minutes, or until a toothpick inserted into the center comes out clean.
Leave to cool. Melt a tablespoon of honey or maple syrup with a tablespoon of hot water, brush the surface, and sprinkle with brown sugar.