directions
1. preheat oven to 350°F. spray a standard 12-cup muffin tin with cooking spray or line with cupcake liners.
2. in a medium bowl whisk together flour, baking powder and salt.
3. in a large bowl or the bowl of a stand mixer fitted with paddle attachment beat butter and sugar until fluffy. beat in spinach, then vanilla. beat in eggs 1 at a time until incorporated, scraping down sides of bowl as needed. beat in milk, then mix in flour mixture until just combined.
4. fill muffin cups ⅔ full and bake until golden, 18-20 minutes. let cool 5 minutes in pan, then cool completely on a rack.
5. in a food processor combine cream cheese, butter, sugar, and vanilla and pulse until smooth and creamy.
6. frost cupcakes with cream cheese frosting and decorate with sprinkles.