Spray an 11x15 baking dish with non-stick cooking spray. (I use a jelly roll pan because the sides are the perfect height for 1-inch tall treats & it makes it very easy to level the mixture.).
In large pan or dutch oven, melt butter over low heat. Add marshmallows & stir until completely melted. (I use a heavy duty Kitchenaid rubber scraper to help chop up the marshmallow chunks & whip the mixture until smooth.).
When marshmallows are melted & smooth, turn off heat & add almond extract & food coloring. Stir well.
Remove from burner & add rice krispies. Stir till combined.
Turn mixture out onto prepared jelly roll pan.
Cut a piece of waxed paper to fit the length of pan & spray one side with cooking spray.
Lay paper, spray side down, on top of mixture. Use hands on top of paper to press mixture firmly into pan. (Be sure to spread evenly into corners & along edges.) When finished, mixture will be slightly below the top edge of pan & level all the way across.
Remove waxed paper & set aside for later.
Let krispies cool in pan for about 5 minutes.
Lay waxed paper over pan again & flip everything over onto counter, cutting board or cookie sheet. Tap bottom of pan & let mixture fall out onto waxed paper.
Spray inside of cookie cutter with cooking spray (repeat as necessary) & cut 6 - 7 hearts out of mixture.
Put each heart into a non-zippered gallon size baggie, gently squeeze air out & tie with ribbons. (I usually trim a couple inches off the top of the baggie after tying.).
I like to tie on handmade name tags or other decorations.