UIButton+Magic.h

@import UIKit;

@interface UIButton(Magic)
- (void)onTouchUpInside:(void(^)(UIButton *button))block NS_SWIFT_NAME(onTouchUpInside(_:));
@end

UIButton+Magic.m

#import "UIButton+Magic.h"
#import <objc/runtime.h>

// A key for the associated object that contains the action block.
static void *_magicActionName = &_magicActionName;

// Declare the _magicAction selector to avoid a compiler warning
@interface NSObject(Magic)
- (IBAction)_magicAction:(id)sender;
@end

// The implementation for the _magicAction selector
void _magicAction(id self, SEL _cmd, id sender) {
    void(^block)(UIButton *button) = objc_getAssociatedObject(self, _magicActionName);
    block(self);
}

@implementation UIButton(Magic)
- (void)onTouchUpInside:(void(^)(UIButton *button))block
{
    Class klass = [self class];
    NSString *klassName = NSStringFromClass(klass);
    NSString *newKlassName = [NSString stringWithFormat:@"_Magic%@", klassName];
    const char *newKlassCName = [newKlassName UTF8String];
    SEL _magicActionSelector = @selector(_magicAction:);

    // Define new class
    Class newKlass = objc_getClass(newKlassCName);
    if (newKlass == nil) {
        newKlass = objc_allocateClassPair([self class], newKlassCName, 0);
        class_addMethod(newKlass, _magicActionSelector, (IMP)_magicAction, "@");
        objc_registerClassPair(newKlass);
    }
    
    // Go
    object_setClass(self, newKlass);
    objc_setAssociatedObject(self, _magicActionName, block, OBJC_ASSOCIATION_COPY);
    [self addTarget:self action:_magicActionSelector forControlEvents:UIControlEventTouchUpInside];
}
@end

ViewController.swift

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var button: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        var counter = 0
        button.onTouchUpInside { button in
            counter += 1
            button?.setTitle("Taps: \(counter)", for: .normal)
        }
    }
}