No Excuses (Willow Creek #6)
Andrea Jenelle

But the ad has been up for six months and he's the only one who's responded.
She does everything she can to keep him at a distance. Like grumble at him and feed him fried baloney sandwiches for dinner.
He does everything he can to make her smile.
An opposites attract, grumpy heroine vs. golden retriever hero, age gap romance.