Preheat the oven to 350 degrees. Grease a 9 inch springform pan, and line the bottom of the pan with a circle of parchment.
Peel and core the pears.
Chop three of the pears roughly and cook in a covered saucepan over medium heat for 10 minutes with the lemon juice and 2 teaspoons of sugar.
Remove from the heat, and roughly mash the pears in to a puree. Let cool. You will want to end up with 2 cups of mashed pears to add to the cake.
Put the almond meal and 1 ¾ cups of sugar in a food processor and pulse 4 or 5 times for approximately 3 seconds per pulse.
Add the eggs, 1 teaspoon of the vanilla, and the cooked pears and puree the mixture. Pour into the prepared pan.
In a small saucepan, heat the honey, ¼ teaspoon vanilla, ½ teaspoon almond extract, and the water until the mixture bubbles.
Slice the last remaining pear into ¼" slices and add the slices to the hot honey mixture. Remove from the pan from the heat and toss gently to coat.
Sprinkle the sliced almonds over the top of the cake. Top with the sliced pears and spoon any remaining honey sauce over the top of the cake.
Bake for 1 hour or until the cake is browned and a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for about 30 minutes, then run the dull side of a knife around the sides of the pan to loosen the cake, remove the sides of the pan, and serve.