I second danon's comment about experiencing two very, very different cultures in Barcelona and Madrid! And I agree with danon about exploring Andalucía in a much less hurried way. Andalucía is very, very wide.

Thx…hard to imagine one wouldn’t wish to explore more of the country after a “ taste”
of Spain 🇪🇸.

First of all, I recommend to taste classic dishes from the regional cuisines of Spain. For example, from the Basque Country: bacalao al pil-pil (cod), chipirones en su tinta (baby squid in their ink), merluza en salsa verde (hake in parsley sauce), txangurro (baked stuffed spidercrab)...
Restaurante Jai Alai https://restaurantejaialai.com/

Good "foodie" tips from a Basque!

We really enjoyed the food tour we did on our first night in Madrid several years ago. It gave us a nice introduction to some of the food, drinks and restaurants in Madrid and was fun. https://www.walksofspain.com

And Culinary Backstreets does a very nice food tour in Barcelona, if you're interested, highlighting catalán cuisine in the less tourist trodden Grŕcia neighborhood.
https://culinarybackstreets.com/cate.../#food-tours-t

Cook & Taste in Barcelona also offers a morning market tour followed by a cooking class.
https://cookandtaste.net/en/