Step 1: Prepare your butter and sugar mixture - Start by placing the softened butter in a large bowl. Add the granulated sugar and brown sugar to it. Use a hand mixer or a whisk to beat them together until the mixture becomes light, creamy, and smooth.

Step 2: Add the egg and vanilla - Once your butter and sugar are well mixed, crack the egg into the bowl and add the vanilla extract. Mix again until everything blends nicely.

Step 3: Mix the dry ingredients - In another bowl, combine the all-purpose flour, protein powder, baking powder, and salt. Stir well with a spoon or whisk so that everything is evenly mixed.

Step 4: Combine wet and dry ingredients - Slowly add the dry ingredients to the butter mixture. Use a spatula or spoon to mix gently until a soft dough forms.

Step 5: Chill the dough - Once your dough is ready, cover it with plastic wrap and place it in the refrigerator for about 30 minutes.

Step 6: Shape the cookies - Preheat your oven to 350°F (175°C) and line a baking tray with parchment paper. Take a small portion of dough, roll it into a ball about the size of a walnut, and place it on the tray.

Step 7: Bake to perfection - Bake the cookies in the preheated oven for 10 to 12 minutes. Watch closely as the edges turn golden but the centers remain slightly soft.

Step 8: Enjoy your healthy treat - Once cooled, your High Protein Butter Cookies are ready to enjoy.