First the manure and cover that with the leaves. I have done this for many years now and find the results to be quite good with the garden ready to plant in the spring.

I keep a large supply of leaves on hand (collecting more throughout the month) and apply a fresh layer over each batch of kitchen scraps.

This keeps the critters out and also allows me a source of carbon that is not "frozen solid" during the cold period. I keep these leaves in a separate bin with a cover and some in their lawn bags.

A good bucket full of water on top of each addition will keep the process working even during the freeze periods. Even if it dies down, it will fire right back up in the spring.

Best!

Here is a link that might be useful: My Gardening Adventure

If the manure is fresh, it should really be composted first. The leaves are best shredded to increase surface area for microbes to work on. A lawn mower will do the job very nicely.

If Marshall were to lay down the manure on top of the soil and cover that with the leaves then the manure would be composted, in situ.

Manure, then leaves, and tuck the kitchen scraps under. If you leave them on top they will dry out and not break down as quickly. Also they look ugly.

Congrats on your retirement project! Isn't retirement wonderful!