Step 1: Cook the turkey bacon by placing 4 slices in a cold skillet. Cook over medium heat, flipping occasionally, until golden brown and crisp, about 6-8 minutes. Transfer to a paper towel-lined plate to drain, then crumble or chop into bite-sized pieces once cooled. Set aside.
Step 2: Prepare the creamy ranch dressing. In a small mixing bowl, combine 1/2 cup sour cream with 1/4 cup mayonnaise. Stir in 1 packet (or 2 tablespoons) of ranch seasoning and the optional 1/2 teaspoon garlic powder. Whisk until smooth and uniform. Season with a pinch of salt and freshly ground black pepper to taste, keeping in mind the bacon and cheese will add saltiness.
Step 3: Prep the vegetables and cheese. In a large salad bowl, add the 2 large cucumbers, diced into roughly 1/2-inch cubes. Ensure the cucumbers are as dry as possible; pat with paper towels if freshly rinsed. Add 1 cup of shredded cheddar cheese and 1/4 cup of chopped green onions.
Step 4: Combine all ingredients by adding the crumbled turkey bacon to the bowl with cucumbers, cheddar, and green onions. Pour about three-quarters of the prepared ranch dressing over the top, reserving the rest for adjustment.
Step 5: Gently toss to coat. Use salad tongs or two large spoons to fold the ingredients together until each piece is lightly coated with dressing. Be careful not to over-mix or crush the cucumbers to maintain their crispness.
Step 6: Adjust seasoning and dressing. Taste a small spoonful of the salad. If desired, drizzle in the remaining dressing for extra creaminess or add a pinch more salt, pepper, or ranch seasoning for more zip.
Step 7: Chill the salad to marry flavors. Cover the bowl tightly with plastic wrap or transfer to an airtight container. Refrigerate for at least 30 minutes, or up to 2 hours, to allow the flavors to deepen.
Step 8: Serve and garnish. Give the salad one final gentle toss before serving. Transfer to a serving dish and, if desired, sprinkle with additional chopped green onions or a few extra bacon crumbles for garnish. Serve cold.