To make fresh pineapple-infused rum: Peel and cut a ripe pineapple into chunks. Place in a large glass container and pour in a 25 fluid ounce bottle of gold Barbados rum (such as Mount Gay® or Trader Joe's® Rum of the Gods), making sure all the pineapple is covered. Store on cool, dark shelf, stirring once a day, until rum reaches desired flavor, at least 1 week but preferably 2. Strain out pineapple. Infused rum keeps for up to 6 months.
You can save the pineapple you strain out to make boozy cupcakes or jam.
Substitute almond orgeat syrup (such as Torani®) for the orgeat syrup if desired.