Rinse the spinach leaving the water clinging to the leaves. Heat a large skillet over medium-high heat. When hot add the wet spinach and cook until wilted, stirring often, 2-3 minutes. When the spinach is wilted, drain in a strainer. Use a wooden spoon to press as much water from the spinach as possible. When cool enough to handle, chop spinach finely, squeezing out more water if possible. Set aside.
In the large skillet you wilted the spinach in, over medium heat, add cream cheese and soften. Once the cheese is soft and creamy, add spinach, artichoke hearts and the remainder of ingredients. Stir until combined then pour into a bowl to cool a bit.
Starting with the thick part of each chicken breast, slice in half horizontally to produce 2 thin pieces. Cover the chicken breast pieces with a sheet of plastic wrap and pound with a meat mallet or the bottom of a small skillet until all of the pieces are about ¼" thick.
When the breasts are ready, spread ¼-½ cup spinach mixture over each breast (depending on size of breast) leaving ¼” edge uncovered. Fold each breast over to completely cover filling. Seal sides using toothpicks then set aside.
Stir flour, salt, garlic powder and onion powder together on a large plate until completely combined. Add beaten eggs to another plate then pour breadcrumbs onto a third plate. One by one, carefully dredge the breasts in the flour and shake off any excess being careful not to shake out the filling. Dip them in the egg to coat completely and then cover in breadcrumbs. Shake off excess and place on a large plate while you bread remaining chicken.
Place a large skillet over medium heat, add enough oil to come ¼" up the sides of the pan and allow it to heat. Working in batches, carefully place cutlets in the hot oil. Cook 2-3 minutes on first side or until nicely golden brown then flip and cook an additional 2–3 minutes or until golden.
Transfer cooked chicken to a rack placed over a baking sheet. Repeat with remaining breasts. Can be made ahead to this point.
Preheat oven to 350 degrees. 30 minutes before serving, place baking sheet in oven and bake 20-25 minutes until centers are 150 degrees. Remove from oven and let rest 5 minutes before serving. Enjoy!
One Last Thing
The most important thing is to make sure that your artichokes and spinach are well-drained. Too much excess moisture could mess with your overall consistency.