Preheat your oven to 350°F. While it heats, line an 8x8 inch baking pan (or similar 2-quart capacity) with parchment paper, allowing some overhang on the sides for easy removal later. This prevents sticking and makes cooling easier.

Cut the unsalted butter into chunks and melt it in a small bowl, then let it cool for a few minutes until it's warm but not hot. In a large mixing bowl, whisk together the cooled melted butter, eggs, vanilla, and sugar until the mixture is pale and well combined, about 2-3 minutes of whisking. The sugar should begin to dissolve and the mixture will become lighter in color—this incorporates air and helps create a tender crumb.

Add the almond meal, salt, baking powder, coconut, and lemon zest to the wet mixture from Step 2. Fold everything together gently with a spatula until just combined—don't overmix, as this can make the cake dense. The batter should come together smoothly with no visible streaks of dry ingredients. I like to add the lemon zest at this stage rather than earlier so its fresh aroma and oils stay vibrant in the finished cake.

Pour the batter from Step 3 into the prepared pan and spread it evenly into the corners. Sprinkle the flaked almonds over the top in an even layer, pressing them down gently so they stick to the batter. The almonds will toast slightly as the cake bakes and add wonderful texture and visual appeal.

Bake the cake in the preheated 350°F oven for 40 minutes, until the top is golden brown and a toothpick inserted into the center comes out clean or with just a few moist crumbs. The edges should pull slightly away from the pan sides.

Remove the cake from the oven and let it rest in the pan for 15 minutes—this allows the structure to set enough to handle safely. Turn the cake out onto a wire cooling rack and let it cool completely for at least 1 hour before serving. I find that waiting the full hour really improves the texture and makes slicing cleaner.