Preheat your oven to 350°F and line a 12-cup muffin tin with paper liners or grease it well. While the oven heats, measure out all your ingredients and bring your egg whites and yogurt to room temperature—this ensures they'll blend smoothly with the dry ingredients and create a lighter, more tender crumb. Dice your strawberries into small 1/4-inch pieces so they distribute evenly throughout the batter, and melt the coconut oil, allowing it to cool slightly before use.

In a large mixing bowl, whisk together the oat flour, vanilla protein powder, baking soda, cinnamon, and salt. Whisk vigorously for about 30 seconds to fully incorporate the baking soda and distribute the cinnamon evenly throughout—this prevents lumps and ensures an even rise. Stir in the coconut sugar, breaking up any small clumps as you go. I like to use a whisk rather than a fork for the dry ingredients because it aerates the flour mixture slightly, which helps create a lighter texture in the finished muffins.

In a separate bowl, whisk together the room-temperature egg whites, yogurt, almond milk, melted coconut oil, lemon juice, lemon zest, and vanilla essence until well combined and slightly frothy. Pour the wet mixture into the bowl with the dry ingredients from Step 2 and gently fold together using a spatula until just combined—don't overmix, as this can develop the gluten and create tough, dense muffins. The batter should look slightly lumpy; a few streaks of flour are perfectly fine. I prefer to use a spatula rather than an electric mixer for this step because it gives me better control and prevents overdeveloping the batter.

Gently fold the diced strawberries and chocolate chips into the batter using a spatula, being careful not to overmix. The strawberries should be evenly distributed throughout so each muffin gets a good amount. Work quickly and gently to keep the batter light and airy.

Divide the batter evenly among the 12 prepared muffin cups, filling each about three-quarters full. Top each muffin with a small pinch of extra chocolate chips for visual appeal and extra flavor pops. Place the muffin tin in the preheated 350°F oven and bake for 23-25 minutes, until the tops are light golden brown and a toothpick inserted into the center comes out clean or with just a few moist crumbs (not wet batter).

Remove the muffin tin from the oven and let the muffins sit undisturbed for 5 minutes—this allows the structure to set slightly so they won't fall apart when you remove them. After 5 minutes, gently tip each muffin out of its liner and onto a wire cooling rack. Let them cool completely before serving, about 20-30 minutes, which allows the crumb to firm up and makes them easier to handle.