Dipping sauce: In a medium bowl combine avocado, mayonnaise, lime juice, lime zest, and 1/4 teaspoon salt. Mash avocado with a fork or spoon, and stir to combine. Set aside.
Batter: In another bowl, combine Pamela's Cornbread & Muffin mix, sugar, and 1/4 teaspoon salt. Stirring constantly with one hand, slowly pour cider into dry ingredients until it forms a loose batter, the consistency of oatmeal. (You will not use the whole bottle of cider.) Stir in the sriracha. If mixture is too loose, add a touch more cornbread mix.
Shrimp: Skewer each shrimp with the end of a bamboo skewer, piercing each shrimp in two places so that it is secure.
Fill a small deep sauce pan about 2 inches deep with canola oil. Set over medium high heat and using a candy thermometer, heat oil to about 315°. Working in batches of three or four, dip each shrimp in batter and use a spoon to coat completely. Drop immediately into oil, and cook 2 - 3 minutes until batter is golden brown and shrimp are cooked through. Remove from oil and drain on paper towel lined plate. Sprinkle with salt. Repeat frying process with remaining shrimp skewers.
Serve immediately with Avocado-Lime Dipping Sauce.
Chef's comment: This playful appetizer provides a lot of impact for a little effort - the whole recipe takes about 20 minutes to complete. Deep frying at home doesn't need to be a big undertaking - a small sauce pan of oil plus a candy thermometer will get the job done.