Spray your 9x5 loaf pan well with cooking spray, ensuring it's coated everywhere with a thin layer. Set aside.

Combine 1/4 cup water and 1 tbsp beef gelatin in the bowl of a stand mixer (or use a metal bowl and hand mixer) and stir together until no lumps remain.

In a small saucepan, combine remaining 1/4 cup of water, sugar, and honey and bring to a gentle boil. Cook until it reaches 240°F (it should take 6-8 minutes, be patient)! Use a candy thermometer to check the temp, or if you don't have one, time it for closer to 8 minutes and watch that the texture becomes like a thick syrup (similar to how the honey started - as you pull the spoon from the mixture it should start to almost make strings resembling hair).

Once boiled down to 240°F, add it into your gelatin mixture in your stand mixer and mix on medium-high for 7-8 minutes, until thick and glossy.

Add in vanilla and protein powder and continue mixing for another 2-3 minutes, until the mixture is opaque, fluffy, and sticky.

Work quickly to scoop the marshmallow mixture into the prepared pan, using an oiled spatula to smooth the top if needed.

Let chill in the fridge for at least an hour before cutting.

To cut, use a sharp knife and cut into cubes. Toss each marshmallow in powdered sugar to prevent them from sticking to everything.

Store in an airtight container in the fridge for up to a week. Enjoy!