In a mixing bowl, whisk together cake flour, cornstarch, baking powder, and salt.

In a stand mixer, cream together unsalted butter, vegetable shortening, and granulated sugar until light and fluffy.

Beat in the egg and egg white, followed by orange zest, orange extract, and vanilla extract.

Gradually add the flour mixture until just combined.

Transfer the dough to an airtight container and refrigerate for 2 to 3 hours.

Preheat your oven to 375°F (190°C) during the last 10 minutes of chilling.

Scoop out portions of dough and flatten each into a disk about ½ inch thick on prepared baking sheets.

Bake for 8 to 11 minutes until soft but set, then cool for 5 minutes on the sheet before transferring to a wire rack.

Prepare the frosting by beating cream cheese and salted butter until smooth, then gradually add powdered sugar and orange extract.

Frost cooled cookies and add sprinkles if desired.