Stir browni mix, water, oil and eggs in a bowl until combined.
Spread mixture in a 9X13 pan that's been lined with parchment paper.
Bake in the preheated oven for 25 minutes or until a toothpick inserted in the middle comes out clean.
Allow the brownies to cool in the pan for 10 minutes before gently lifting the ends of the parchment paper. Place on a cooling rack to cool completely.
Gently press heart shaped cookie cutters into the cooled brownies.
Decorate with powdered sugar and sprinkles if desired.
Notes
Make sure the brownies are completely cooled before cutting out shapes.
To store leftover brownies, place them in an airtight container or wrap them tightly in plastic wrap. This will help prevent them from drying out and keep them moist.
Store the brownies at room temperature or in a cool, dry place.