Preheat oven to 325ºF and lightly grease 24-cup mini muffin pan; set aside.
Make Flax Egg: In a small bowl combine flaxseed meal with water and set aside for 5 minutes.
Melt chocolate: In a small saucepan over low heat, melt chocolate chips, stirring until smooth. Or melt on 50% power in 30 second increments, stirring until smooth. Set aside and let cool slightly.
Mix wet ingredients: In a large bowl, mix together cashew butter with oil and sugar until fully combined. Add in melted chocolate and vanilla extract until smooth. Add in flaxseed "eggs" until combined – mixture will get thicker at this point.
Add dry ingredients: Gently add in flour, cocoa powder, baking soda and salt, stirring until smooth, adding milk at the end until batter is thick and fudge-y.
Scoop dough: Using small cookie scoop, evenly distribute batter into mini muffin pan, filling 3/4 way full (any more and you'll over flow the tops).
Bake brownie bites for 8-10 minutes (mine took 9 – test for wet batter with toothpick). Allow brownies to cool completely before carefully removing from pan (I used a butter knife to gently lift).
Prepare strawberries: While the brownies are cooling, wash and dry strawberries, then cut off green tops. You'll need 24 large strawberries. Make the frosting: In a medium bowl using electric mixer, cream butter until smooth then carefully add powdered sugar, mixing on low speed until combined. Taste test for desired sweetness after 1 cup.
Assemble Santa Hat Brownies: Using piping bag, pipe the frosting around the edge of brownie (option to pipe the entire brownie). Place strawberry on top of frosting, top down, then pipe a dot of frosting on tip of strawberry to create the top of the hat. Continue this process until all of the santa hats have been created.