Preheat the oven to 375*. Oven temperature is important here! It's low enough these can bake for a while, and high enough to brown the tops of the muffins. This is how you achieve tender jumbo blueberry muffins!
In a medium-sized bowl, combine the dry ingredients of flour, salt, and baking powder. Stir together with a whisk and set aside.
5½ cups all-purpose flour, 1½ teaspoons salt, 2 teaspoons baking powder
In a separate bowl, (I'd use a large-sized mixing bowl), combine butter and sugar with an electric hand mixer (or wooden spoon) until well blended.
3 cups white sugar, 1 cup butter
Add in eggs, mixing each one into the batter completely before you add the next egg.
5 eggs
Once all eggs are well combined with your wet ingredients, add in the flour mixture a little at a time until all dry ingredients are incorporated.
5½ cups all-purpose flour, 1½ teaspoons salt, 2 teaspoons baking powder
Stir in half and half and mix until the entire bowl of batter is well combined.
1½ cups half and half
With a rubber spatula, gently fold in the blueberries so you don't smash them.
1½ cups frozen blueberries
Spoon batter into a lined (or greased) muffin pan or paper baking cups, and divide batter evenly among the cups.
Bake the muffins at 375* for 25-35 minutes (depending on your pan/tin/cup size), until the tops of muffins have a light brown color and the center of your muffins are cooked through.
Let muffins cool slightly on a cooling rack before serving. But do serve them warm! They are delicious!