In the bowl of a stand mixer, cream the butter and brown sugar until light and fluffy, about 2 minutes. Mix in the vanilla. Slowly add the flour, scraping down the sides of the bowl as needed.
With the mixer still running, slowly pour in the sweetened condensed milk. Once it is fully combined, stir in the chocolate chips.
Form the dough into 1-inch balls, then shape into eggs by gently flattening each. Place on a wax paper or silicone lined pan, cover loosely with plastic wrap, and refrigerate for a few hours or overnight.
Melt the candy melts according to the directions. Keep the truffles in the refrigerator, removing 3 or 4 at a time, and dip each into the candy melts with a fork. Gently tap off the excess and place on wax paper, parchment, or silicone mat to let set. Decorate with colored candy melts or sprinkles.