Pour the cold water into a large bowl and sprinkle the gelatin on top. Let sit for 5 minutes. Pour the cream and sugar into a pot and set to medium-high heat. Stir to dissolve the sugar and heat until the mixture starts to bubble. Remove from the heat and add the gelatin. Whisk to combine. Add the milk and a drop of pink food coloring to create a peach color.
Set the brain-shaped mold into a bowl to keep it level, then fill with the panna cotta mixture. Place in the fridge and chill overnight until the panna cotta has set.
Wrap a warm dishcloth around the mold to slightly warm the mold, then turn the brain out onto a serving plate. Enjoy!