To start, preheat the oven to 375 degrees Fahrenheit.
Add your dry ingredients together into a medium bowl and mix them until all ingredients are well incorporated.
Then, thaw out the frozen spinach. This can be done quickly by placing the frozen spinach in a microwave-safe bowl and zapping it for 30 seconds.
Using a small blender or immersion blender, blend the spinach and milk together. Then, strain the green milk so any chunks of spinach will be separated out.
Add the green milk to the dry ingredients, along with all the other wet ingredients, and mix well.
Add in the white chocolate chips and cranberries and stir well. The batter will be thick.
Then, add spoonfuls of the batter onto a Silpat lined or parchment-lined baking tray, to form rough mounds or muffin tops, and bake these in the 375-degree oven.
When these are done, remove them from the oven and let them cool for about 20 minutes before you remove them from the Silpat or parchment. Then enjoy with a hot cup of coffee or tea.