Place shells on a baking sheet and fill bottoms with chocolate chips, about 8-10 chips per shell. Bake at 350 for 5 minutes to soften chocolate. Mash down with the back of a small spoon [a baby spoon works well] then spread with 1/4-1/2 tsp almond paste.
Mix ricotta with sugars and vanilla. Place a heaping tablespoon on top of each tart. Sprinkle with orange zest and chopped pistachios.