In a Donor Advised Fund you make an irrevocable gift of at least $5,000 to a managing agency. They in turn invest the funds and keep the records. From time to time you request of them a payment to a charity or charities of your choosing. They honor your recommendation. After setting up the fund you may add to it, change your charity recommendations, grant to others the right to make recommendations, and make provisions for its continuation after death, if you so desire.
Among the agencies which offer donor advised funds are universities, hospitals, Community Foundation of Middle Tennessee, Fidelity Advisors, T. Rowe Price, and Vanguard. They provide tax, investment, and accounting services on their funds. Each has its own regulations and costs, which you should carefully investigate and understand. (Those named here are for information, not an endorsement.)