Preheat Oven and Prepare Pan: Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease with butter or non-stick spray.
Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
Cream Butter and Sugar: In a large bowl, use an electric mixer to cream the softened butter and sugar until light and fluffy. This should take about 2-3 minutes.
Add Eggs and Vanilla: Beat in the eggs one at a time, then stir in the vanilla extract. Ensure each egg is incorporated before adding the next.
Combine With Dry Ingredients: Add the dry ingredients to the wet mixture alternately with the milk, starting and ending with the flour mixture. Mix until just combined; do not overmix.
Fold in Strawberries and Chocolate Chips: Gently fold the diced strawberries and chocolate chips into the batter.
Gently fold the diced strawberries and chocolate chips into the batter.
Prepare Muffin Tins: Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.
Add Optional Topping: If using, mix the sugar and cinnamon together and sprinkle over the tops of the muffin batter before baking.
Bake: Bake for 20-25 minutes, or until the muffins are golden on top and a toothpick inserted into the center of a muffin comes out clean.
Cool and Serve: Let the muffins cool in the pan for about 5 minutes, then transfer them to a wire rack to cool completely.