The sequel to The AppleDash Project, but that was episodic you can jump right in! All you need to know is:

Applejack and Rainbow Dash have been together for more than a year now. Their relationship has blossomed through Discord, a changeling army, and a whole hoof full of crazy situations and dumb mistakes. They've managed to form a partnership and learned to work out their problems together, not an easy lesson for two tough, stubborn ponies.

But now Rainbow Dash is convinced that their lives are getting boring, and if there's one thing Dash doesn't like, it's boring. So Dash has set out to make her relationship with Applejack more interesting. . . and AJ's not so sure she likes that sound of that.

From the original AppleDash Project:
The AppleDash Project is a series of short fics attached to various episodes, detailing a relationship between Rainbow Dash and Applejack behind the scenes. The stories take place sometime during or shortly after the indicated episode.

This is not meant to start shipping wars, argue that AppleDash is canon, or offend other shippers. In fact, if you like the idea I encourage you to try it with other ships!

Teen rating means that there may be talking about sex, but nothing on screen. Expect sitcom-like innuendo.

Applejack couldn't be happier with her life. She owns a great farm and has been married for three years to the love of her life, Rainbow Dash. It's everything she's ever wanted in life, but now she wants something more. A family. A foal. Can she convince Rainbow Dash that they are ready to take a new step in their lives or will a haunting secret from Dash's past prevent them from having one?

(I know a story called "Foal" already exists, but I had this idea for months and I couldn't come up with a different title)

Everyone knows that two mares can't have a foal. . . unless their best friend is one of the greatest magical minds in Equestria.

Applejack and Rainbow Dash went to Twilight Sparkle with a simple question: Could she make a spell that would allow them to have a foal together? After a year of magical research, Twilight thinks that she's done just that. But the spell is not without potential side effects, and AJ and Dash have to decide if they're ready to be part of a magical experiment that could give them a foal of their own, or cost Applejack her life.

Thanks to DbzOrDie and Jackie for proofreading, and to KrazyTheFox for the cover image.