Place all the nuts nuts in a food processor and grind until you obtain a fine powder. Set aside.
Place eggs and sugar/keto sweetener (whichever using) in a mixing bowl and beat with an electric whisk until pale and frothy (3-4 minutes). Add spices and citrus zest and combine. Fold in the ground and baking powder and stir well to combine. Let sit for 5 minutes to firm up.
Preheat oven to 350°F. Line two baking sheets with baking parchment. Rub a thin film of soft butter onto the parchment (these cookies tend to stick to some types of parchment).
Place heaping tablespoonfuls of dough on the baking sheets, leaving about ½ inch distance between each cake. Smooth their surfaces with the back of a lightly moistened spoon. Bake at the center of the oven for 12-15 minutes until risen and lightly golden.
Remove the baking sheets from the oven and leave to cool for 10 minutes before lifting the cakes off with a spatula and setting them on a wire tray to cool completely.
Place ⅔ of the chocolate chips in a microwave proof bowl and heat on 50% power for one minute. Stir and heat for another minute on 50%. Stir again; if the chips haven’t melted, heat for another 30 seconds at 50% power. Now add the remaining chips to the warm chocolate and stir until they have melted. (This is to temper the chocolate so it stays nice and shiny once it's been brushed onto the cakes.)
With a pastry brush, cover the cakes with a thin layer of chocolate and cool on a wire rack (or drizzle chocolate onto the cakes by letting it drip off a teaspoon. If desired, decorate with almond slivers.
These cakes keep about two weeks in an airtight container at room temperature. They are meant to be soft and moist rather than crisp and dry,, like cookies.