Configure / Change JQuery AJAX Encoding

I am making a basic PATCH call like this one:

.ajax({
    url: "/foo/bar/"
    type: "PATCH",
    dataType: 'json',
    data: {
        "foo": "foosball",
        "bar": "bars on bars"
    },
    ...
});

Jquery automatically encodes the data, which leaves "bars on bars" like "bars+on+bars". Is there a way to change the encoding so that spaces are replaces with %20 rather than pluses?

I've noticed this thread that didn't seem to lead anywhere.

I've also taken note of encodeURI and encodeURIComponent but haven't gotten either to work. Both seem to result in the string being double encoded, leaving me with bars%2520on%2520bars

summary:

What I start with: ... "bars on bars" ...

What the received data looks like after jquery encodes the request: "bars+on+bars"

What I need the received data to look like: "bars%20on%20bars"