Arrange the cucumber slices on a baking sheet lined with paper towels or a tea towel. Season both sides of the cucumber rounds with salt. Let sit at room temperature for 20-30 minutes.

Meanwhile, combine the cream cheese, mayonnaise, sour cream, lemon juice, garlic powder and a few grinds of pepper together in the work bowl of a stand mixer. Using the whisk attachment mix until light and fluffy, about 3 minutes, scraping down the sides of the bowl as necessary. Add the chopped dill and mix again until it is evenly dispersed throughout the mixture. Add salt and pepper to taste. (Alternatively, use a hand mixer or whisk by hand. See note below).

Wipe any moisture and excess salt from the cucumber slices and arrange them on a serving platter. Using a metal measuring spoon, create a small divot in the center of each cucumber round. Top each slice with a dollop of the cream cheese mixture and any additional desired toppings. Serve immediately or transfer to the refrigerator for a couple of hours prior to serving.