Bring a large deep saucepan with at least 5 to 6 cup of water to boil. Add about 1 tsp vinegar for each cup of water.(Taste to make sure the amount is correct-vinegar should be barely noticeable). Lower heat to a slow simmer. Carefully crack egg into a teacup or large ladle. Lower teacup or ladle into water and pour egg out as gently as possible,careful not to break yolk. Egg white will coagulate in water and turn white. Cook until egg white i formed and set and yolk begins to thicken but is not hard, 3 to 4 minutes. Remove egg with slotted spoon or strainer; set aside.
Heat a medium nonstick pan over medium heat and mist with cooking spray. Once pan is hot, add spinach and saute for 1 to 2 minutes, until slightly wilted. Remove spinach from pan and set aside.
Toast English muffin. To assemble, spread 1/2 tbsp cream cheese on each half of English Muffin. Place spinach on bottom half of muffin, then add poached egg and tomato. Season with salt and pepper. Finish with hot sauce, if desired before topping with other half of muffin.