Place the spinach, cheese, cream cheese, salt, and cumin into a food processor. Blend until smooth, stopping to scrape down the sides of the bowl as needed.
Divide the spinach mixture between 2 slices of bread and spread evenly. (You can use less of the mixture if you prefer.)
Warm a skillet over medium heat. When warm, add butter to the skillet to melt.
Add the bread slices with filling and swirl to coat with butter. Top with the remaining slices of bread and cook for 4 minutes. Flip over, swirl to coat bread with remaining melted butter In the pan and cook for an additional 4 minutes or until golden brown and filling is melty.
Cut in half, into strips or dice up with kitchen scissors and serve warm.
Notes
You can store any leftover spinach mixture in an airtight container in the fridge for up to 3 days.
Use baby spinach or regular size spinach leaves with the stems discarded.
Let cool for a minute or two before slicing.
Use less filling on the bread if you prefer.
I like to melt the butter in the pan, then swirl the bread around to coat it. You can also spread the butter right onto the bread if you prefer.