Looked but didn't see the recipe. Here is a copy I saved from quite a while back:

Squirrel Block Test Recipe (Revised 12/08)
Makes approximately a 4-week supply for a 1-pound squirrel.

Preheat oven to 225 degrees.

Dry ingredients:
2 scoops* Pure Whey Protein Isolate (7 scoops for growth formula)
2 scoops pecan meal or ground pecans
1 scoop almonds, chopped fine
1 scoop walnuts or pecans, chopped fine
1 scoop wheat bran, unprocessed (this is optional; some squirrels don’t like it)
2 tsp aluminum-free baking powder

*The "scoop" is the one that comes inside the Protein Isolate jar (=28 grams, or 2 1/2 tbsp).

Vitamin mix:
8-16 mg thiamin
6-12 mg riboflavin
60 mg niacin
12-24 mg B-6
100-200 mcg B-12 (note: micrograms, not milligrams)
2,000 mcg folic acid (note: micrograms, not milligrams)
2,000 mg Vit D
12,000 mg calcium**
4 tablets potassium gluconate (595 mg)

**It is fine to use calcium with Vit D, but you will also have to add some plain calcium to get the right amounts. Do not exceed the amount of Vit D by more than 10%.

Wet ingredients:
1 whole egg
1 scoop plain nonfat yogurt
1 scoop natural peanut butter (2 1/2 tbps)
2 gels Cod liver oil (1,000 mg each)
1 tsp vanilla or almond extract
1/2 cup water, or a little more, as needed (this is for growth formula only; do not add to the adult formula)

Place dry ingredients in a large bowl and mix well.

Crush vitamins to a fine powder (a coffee grinder works well) and place in another bowl. Add wet ingredients and mix well.

Add the wet ingredients to the dry ingredients and mix with a fork until dough sticks together. It will be fairly dry, like a pie crust or heavy cookie dough. Wearing gloves or with your bare hands, form the dough into a ball and place it onto a lightly greased surface and knead well. Roll dough out into 4 rolls about an inch thick and place on a lightly greased baking sheet. Bake for 60 minutes. While still warm, cut into 60 pieces with a sharp knife

Allow the blocks to cool for at least 2 hours. Then place into zip-lock bags and store them in the freezer. They keep very well in the freezer for at least a month. Some squirrels enjoy eating them frozen, but you can also put the frozen block into the microwave for about 10 seconds to warm it up.

Feed 2-3 per day for a 1-pound (450 g) squirrel. Different squirrels will have different energy requirements.