It means to have something positively, right across the board.
Spades in a deck of cards is considered the highest point counting group of cards of the four suits in the deck. To have it in spades, means you are fortunate to have the highest level of satisfaction, or respect, or integrity or whatever you can refer to being the best of the best
Without question and beyond doubt
EX1: Minnesota girls have hotness in spades!
EX2: She has dance moves in spades.