Combine all ingredients except gelatin in a small saucepan over medium-low heat. Stir with a whisk.
When it comes to a simmer gradually sprinkle and whisk the gelatin into the mixture, stirring constantly. (Avoid dumping gelatin into pan all at once, which will cause big globs of gelatin to remain in finished product.)
Continue heating over medium-low heat until it comes to a simmer and all ingredients are well combined and gelatin is completely melted. (The mixture will change from a grainy, jelly-like consistency to a more glassy, smooth consistency when gelatin is all melted.)
Take it off the heat and pass it through a sieve to remove any gelatin of fruit bits. If there are bubbles on top remove with a spoon.
Place the heart shaped mold on a cookie sheet (which makes it easier to move without spilling once filled). Pour mixture into silicone mold and place in the fridge for a minimum of 6 hours. Any air bubbles that appear just pop with a toothpick.
Carefully pop the hearts out of mold and store in an airtight container in the fridge. They will keep in the refrigerator for a few weeks.