Mitchell Robinson gave himself a birthday gift — and the Knicks a jolt of energy they’ve been waiting to feel again.

But with the Knicks down Karl-Anthony Towns (left knee soreness) for their 105-91 win over the depleted 76ers on Tuesday, Robinson, on his 27th birthday, took the latest step toward normal with the playoffs nearing by collecting 14 points, seven offensive rebounds — which directly led to six second-chance points — and 14 total boards.

New York Knicks center Mitchell Robinson has been back for a month, and his presence has been felt. Since his return to the team on Feb. 28, the Knicks have bee