In a large mixing bowl, cream together 2/3 cup of room temperature unsalted butter, 6 tablespoons of sugar, and 1/4 teaspoon of salt until light and fluffy. Add 1 1/2 cups of finely ground almonds and mix until just incorporated. Then, add 3 large eggs and 1/4 teaspoon of almond flavoring, mixing again until just incorporated. Grease your baking dish with some additional butter, then spread the almond mixture evenly across the bottom of the dish. I like to use a spatula to ensure an even layer—this helps the almonds bake up nice and tender.

Pre-heat your oven to 350°F (180°C) with a rack in the middle. Peel, core, and quarter 4 to 5 large fresh pears. Arrange the pear quarters over the almond mixture in the baking dish, spacing them about 1/2 inch apart and gently pressing each piece into the almond mixture so they are slightly tucked in. You may not need all the pear quarters, so avoid overcrowding the dish.

Evenly sprinkle 2 tablespoons of sugar over the arranged pears. Place the baking dish in the preheated oven and bake for 40 minutes, or until the top is lightly golden. Check for doneness by inserting a knife or toothpick into the almond mixture; it should come out clean when the gratin is cooked through. I like to let it cool just slightly in the pan so the flavors settle before serving.

Once the gratin is out of the oven and slightly cooled, optionally dust the top with confectioners' sugar. Serve warm or at room temperature. For a touch of extra indulgence, I highly recommend serving this with a scoop of vanilla ice cream or a dollop of freshly whipped cream.