Preheat oven to 350 degrees Fahrenheit.
Rub a generous amount of soft butter on the inside of an 8.5-inch springform pan.
Make the crust by placing the cookie crumbs and sliced almonds in a food processor. Pulse until finely ground. Add in 2 tablespoons sugar and the melted butter. Pulse until combined.
Firmly press the crumb mixture into an even layer in the bottom of the buttered pan.
Bake for 15 minutes. Let cool completely.
Reduce oven heat to 300 degrees Fahrenheit.
Make the filling. Whisk the egg yolks and 1/3 cup of sugar until it becomes pale in color. Mix in the ricotta, almond extract, vanilla extract, lemon zest and a pinch of salt. Set aside.
Beat the egg whites until stiff peaks form. In batches, slowly fold the egg whites into the ricotta mixture.
Pour the filling into the springform pan on top of the prebaked almond crust. Spread to ensure an even layer of filling all the way around the pan.
Bake approximately 1 hour 15 minutes, until deep golden color around the edges.
Let cool.
Gently run a knife around the edge of the pan. Remove springform.
Serve chilled or at room temperature.