Place frozen corn in a food processor and pulse until it's roughly chopped.
Preheat oven to 375 degrees F.
In medium bowl combine butter, masa harina, and water, and milk and beat until creamy.
In a small bowl whisk together the corn meal, sugar, baking powder and salt. Add to the wet ingredients and beat until smooth.
Add the chopped corn and stir to combine.
Grease a regular size muffin tin with cooking spray. Spoon the batter into the cups, filling them about 1/2 full (it should make about 10).
Bake at 375 degrees F for 15-18 minutes or until set and a toothpick inserted in the center comes out clean. I found it easiest to get them out by placing my cooling rack down on top of the muffin tin and then flipping it over all together, so they come right out.
Cover the bottom of your serving tray with a a thin layer of salsa verde.
Place the tamale cakes on top of the salsa verde. Spoon pico de gallo on top of the tamale cakes.
Add a dollop of sour cream and a few chopped avocados. Drizzle with southwestern sauce.
For the Southwest Sauce: whisk all ingredients together in a small bowl.