Preheat oven to 350F. Coat a 9-inch spring form pan with cooking spray. Line the bottom with parchment paper and spray the paper.
Beat egg yolks, honey, vanilla, baking soda and salt in a large mixing bowl with an electric mixer (or use a paddle attachment on a stand mixer) on medium speed until well combined. Add the ground almonds and beat on low until combined.
Beat egg whites in another large bowl with the electric mixer (use clean beaters on a hand-held mixer or the whisk attachment on a stand mixer) on medium speed until very foamy, white and doubled in volume, but not stiff enough to hold peaks, 1 to 2 minutes (depending on the type of mixer). Using a rubber spatula, gently fold the egg whites into the nut mixture until just combined. Scrape the batter into the prepared pan.
Bake the cake until golden brown and a skewer inserted into the center comes out clean, 25 to 28 minutes. Let cool in the pan for 10 minutes. Run a knife around the edge of the pan and gently remove the side ring. Let cool completely.
If desired, remove the cake from the pan bottom by gently sliding a large, wide spatula between the cake and the parchment paper. Carefully transfer the cake to a serving platter. To serve, drizzle the top of the cake with honey and sprinkle with sliced almonds.