Barcelona to Granada/Malaga

There are few routes between those two cities and you’ll drive the coast until Alicante where you turn inland. Most of the towns along the coast are heavily touristed. Valencia would be a good place to visit. An alternative route would be to drive to Valencia then go west to Manzanares, then turn south to Granada. Either route is a 9 hours drive without stops. A final alternative route would be to drive to Zaragoza, then Madrid, before turning south. That route adds a couple more hours of drive time.

There are a number of places you could stop, but with the very limited time you have, I’d select only one.

Very helpful. Is there a high speed train from Barcelona to Alicante? If we are just staying a night on the sea, wondering about taking a train there and then renting a car from Alicante to Granada? Or are there cheap flight options?

That's a lot for a week--how many days do you intend to spend in Barcelona, Granada, and Malaga? I would determine all of that before I chose transport.

We are flying in to Barcelona and out of Malaga. We want to spend three nights in Granada, have tickets to the Alhambra, etc. So we have three nights between flying in to Barcelona and arriving in Granada. We'd love to train along the coast, but for the life of me, I cannot figure out which trains go from Barcelona down the coast without them going to Madrid first. Isn't there a train that goes that way? We wondered about renting a car in Alicante and then driving to Granada.

The other option is to look into in-country flights, I suppose. We're going to Barcelona but do prefer smaller cities. Thanks again for this help!

I am still not clear if you will actually spend any time in Barcelona or Malaga--I assume you'll need at least a night in Malaga (and it is a pleasant town), depending on your outbound flight time.
I can only suggest checking all of your train options on the Renfe site by date to see what all of your options are. I'd be reluctant to drive that much for short stays, but that's just a personal preference. Flying is not ideal either, but sometimes time dictates those choices!
Right now, results are not showing up--it may be that the fall schedules are updated later.

Good question. This is what we're thinking now:

Day 1: arrive in Barcelona early, sightsee.
Day 2: La Sagrada Familia and Park Guell
Day 3: (hoping for a lovely scenic trip) train to Valenica/Alicante (spend night in Alicante?)
Day 4: rent car in Alicante and drive to Granada
Day 5: Alhambra
Day 6: wander in Granada
Day 7: drive to Malaga early, wander
Day 8: fly out of Malaga

Our 12 year old's goal is to eat as many churros as he can (haha). And we love small towns, but have never been to Barcelona so thought we'd try to do a bit of sightseeing on this trip. Does this seem reasonable? I know it's a lot for one week, but it is what it is and we want to maximize. I did think about flying to Seville from Barcelona, but I've done Seville a couple of times and we are hoping to see some new things.

Now that you have it all written out, looks manageable, just need to sort those transport details. I think you can get as fast as a three-hour train from BCN to Valencia. Maybe a book like DK Eyewitness Back Roads Spain would help with planning your drive portion. If you have to drive that long, might as well make it pack a punch! And follow up with James as the trip fleshes out of course--he's driven all over Spain!

Someone else will have train information. We almost always have a rental car when we visit.

To be honest, if I was going to drive from Barcelona to Malaga I would need between 2 and 3 weeks to see the places I have bookmarked and to do it at a leisurely pace. Leisurely meaning no more than 2.5 hours driving a day and spending a couple nights at each place we decided to spend a night at.

I think you are adding more "travel time" to the trip and gaining less opportunities to create wonderful travel memories.
On Day three from hotel to hotel you will spend six hours in travel time.
On Day four from hotel to hotel you will spend six hours in travel time.
This means you will have less than a half day to explore Alicante?????
So I am unsure of what the purpose is for visiting Alicante?
Barcelona offers a huge menu of opportunities of varying sizes in experiences. Essentially you have six and a half days to create travel memories. Please consider the following:
Rent an apartment an gain some extra space plus the kitchen (wonderful to have some control of creating your own breakfast and storing some market purchased foods)
Day 1: arrive in Barcelona early, settle into apartment then go stretch legs. Start with a walk around the block of your accommodations to identify places to eat, shop and drop into interesting places to gain your bearings. Visit Plaza Catalunya and stop in at El Corte Ingles. Bathrooms are on top floor and the restaurant is also good. In the basement is a full grocery store which our girls loved finding different food to experience. Shop the market on your way back to the apartment to ease the carrying of food.
https://www.elcorteingles.es/centroscomerciales/en/eci/centros/centro-comercial-placa-de-catalunya
STAY OFF RAMBLA for it is now a pick pockets delight.
Unsure of your families interest, but the menu is wide for having something to offer everyone. Do your best to stay up later on first night for adapting to local culture time clock will expand your vacation hours.
Strongly suggest going to Tapas bar and allowing your 12 year old to choose selections based upon eye appeal. Expanding the palette can create great memories and even if the selection is a "thumbs down" the cost is minimal for experience.
Day 2 - 5 Stay in Barcelona. The subway and train system is seamlessly connected offering ez day trips to a variety of interesting experiences.
Day 5: Morning Flight to Granada. On Vueling about $100 each direct with 1 1/2 hours flight time or five hours from door to door.
Day 6: wander in Granada
Day 7: Bus to Malaga in late afternoon, wander old town Malaga in evening
Day 8: fly out of Malaga

This itinerary provides maximum opportunity to be there more with less travel stress.
You stay in three different accommodations with only one "overnighter" in Malaga.
You spend five hours in transit from Barcelona to Granada and three hours in transit from Granada to Malaga. Bus stations are ez to access and the Spain bus experience is great plus cheap.

I love Valencia and like Alicante, but cannot make sense of the travel investment in terms of time and money to be there for such a short period of time.

Suggest creating a new post titled "What can we do in Barcelona for five days with a 12 year old?".
I suspect you will obtain a number of posts expending your knowledge of opportunities.
BTW, will help to know child's gender and interests along with your interests.