Preheat your oven to 300°F (150°C). Spread the all-purpose flour evenly on a baking sheet and bake for 10 minutes to heat-treat it; allow it to cool completely.

In a large mixing bowl, cream together the unsalted butter, granulated sugar, and light brown sugar until light and fluffy, about 3-4 minutes. Mix in whole milk and vanilla extract, then slowly add the cooled flour and salt, stirring until combined. Fold in mini chocolate chips.

Transfer the cookie dough onto wax paper and flatten to about ½ inch thick. Freeze for 15-20 minutes until firm. Use a heart-shaped cutter to cut shapes and refreeze for 10 minutes.

In a microwave-safe bowl, combine semi-sweet chocolate chips and coconut oil. Microwave in 20-second intervals until smooth and melted, about 1-2 minutes.

Dip each heart into the melted chocolate, ensuring all sides are coated evenly. Place on a wax paper-lined sheet. Add sprinkles before the chocolate hardens.

Transfer the baking sheet to the refrigerator and chill for 30 minutes until the chocolate is set.