Combine protein powder, collagen, peanut flour, monk fruit, and salt in a food processor.
In a small bowl, stir together the butter, water, and vanilla extract.
With the food processor running, stream the butter mixture in. Process until the batter comes together in a large ball. Add water a tablespoon at a time and process well to ensure it is incorporated before adding more if it seems too dry. Add a bit more almond flour if it seems too wet.
Remove half the dough and reserve. Add the strawberry extract and color, if using to the remaining dough and process until smooth.
Crumble the two doughs together to form a mottled, ripple effect and press into an 8×8-inch pan lined with parchment or plastic wrap.
Refrigerate until cool and set, about an hour, slice into 12 bars and wrap individually with parchment paper. Store in the refrigerator until eating as they can spoil. These can be taken for travel and will not melt although they will get quite soft and tacky when warm.