To Make The Crema, In A Small Bowl, Combine Sour Cream, Cilantro, Lime Juice, Jalapeño, Salt, And Black Pepper.
Set Aside.
To Make The Pitas, Cook Squash According To Package Directions, Then Add To A Large Bowl.
Stir In The Garlic, Butter, Chili Powder, Salt, And Pepper.
Mash Together With A Fork.
Set Aside.
In A Small Microwave-Safe Bowl, Microwave Beans On High Until Hot, About 1 Minute.
Warm Pitas In The Microwave, About 15 Seconds Each, Then Evenly Divide The Squash, Beans, Queso Fresco, And Avocados Across The Tops Of Each.
Top With The Cilantro Lime Crema And Serve Immediately.