Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish, prepare the cake batter according to package directions, pour into the pan, and bake 28–33 minutes until a toothpick comes out clean.
Let the cake cool in the pan for exactly 15 minutes, then use the handle of a wooden spoon to poke 40–50 holes evenly across the surface, pushing nearly to the bottom and twisting slightly to widen each hole.
If ricotta is watery, drain it through a fine-mesh strainer for 10–15 minutes. In a large bowl, beat cold heavy cream on high speed for 2–3 minutes until stiff peaks form.
In a separate bowl, beat ricotta, powdered sugar, vanilla extract, and almond extract on medium speed until smooth, then gently fold in the whipped cream, chocolate chips, and orange zest (if using) until just combined.
While the cake is still slightly warm, pour half the filling over the surface and press it into the holes with a spatula, then spread the remaining filling evenly on top.
Cover tightly with plastic wrap (pressing it against the filling surface) and refrigerate for at least 4 hours, or preferably overnight.
Just before serving, dust the top with powdered sugar through a fine-mesh sieve and sprinkle reserved mini chocolate chips on top, then cut into squares and serve chilled.