For the cupcakes: Preheat the oven to 325 degrees F and line muffin pans with paper liners.
Sift the cake flour, granulated sugar, baking soda and salt into a large bowl.
In the bowl of an electric mixer fitted with the paddle attachment, combine the buttermilk, oil, vanilla and eggs. Slowly add the sifted ingredients to the wet ingredients and mix until just combined. Fold in the orange zest.
For the cheesecake: In the bowl of an electric mixer, place the cream cheese and beat until smooth and creamy.
Add the ricotta and granulated sugar and beat until smooth, 2 to 3 minutes. Beat in the cornstarch.
Add the eggs one at a time and beat in.
Add the mini chocolate chips and vanilla until everything is beaten in smoothly.
For the crust: In small bowl, combine the pistachios, butter and granulated sugar.
To assemble: Put 2 teaspoons of the pistachio crust into the bottom of each cupcake liner.
Pour a heaping 1/4 cup batter over the top of the crust.
Put the cheesecake mixture into a piping bag and fill up the rest of the cupcake liner until it is a little past three-quarters full.
Bake, 17 to 19 minutes. When cool enough to handle, transfer the cupcakes to a sheet pan and place in the fridge while you prepare the frosting.
For the frosting: In an electric stand mixer fitted with the whisk attachment, beat the cream cheese and butter until light and fluffy and all the lumps have disappeared. Beat in the ricotta and vanilla. Slowly add the powdered sugar and beat until combined.
Frost each cupcake with the ricotta cheese frosting.
