Add the pumpkin puree, eggs, Greek yogurt, and your chosen sweetener into a large mixing bowl. Using a whisk or spoon, mix everything together slowly until the batter becomes completely smooth and well combined. Take a moment to break up any egg streaks or yogurt lumps so the mixture looks creamy and uniform.

Add the dry ingredients—protein powder, flour, spices, and baking powder—into the same bowl. Gently fold everything together using a spatula or spoon. Mix just until combined, making sure there are no dry pockets left. Avoid overmixing, as this can make the donuts dense instead of soft and fluffy.

Carefully spoon or pipe the batter into your donut molds, filling each cavity evenly. Try not to overfill—about three-quarters full is ideal—so the donuts have room to rise and keep their shape while baking. Smooth the tops lightly if needed.

Place the filled donut pan into a preheated oven at 180°C (350°F). Bake for about 12–15 minutes, or until the donuts are set and lightly golden. You can gently touch the surface or insert a toothpick to check doneness—it should come out clean.

Remove the pan from the oven and allow the donuts to cool for a few minutes inside the pan. Then carefully transfer them onto a cooling rack or plate. Let them cool completely before handling further, as this helps them firm up and prevents breaking.

Once cooled, add any toppings you like—such as a light yogurt glaze, a sprinkle of cinnamon, or chopped nuts. Serve immediately or store for later, and enjoy your soft, high-protein pumpkin donuts.