In a medium bowl, combine the softened cream cheese, dill, lemon juice, garlic powder, salt, and black pepper. Mix until smooth and well combined.
Lay out the slices of bread on a clean surface. Spread a generous layer of the cream cheese mixture on each slice.
Place a layer of cucumber slices on half of the bread slices. If desired, add a few lettuce leaves on top of the cucumbers.
Top with the remaining slices of bread, cream cheese side down, to create sandwiches.
Cut each sandwich into quarters or halves, depending on your preference. Serve immediately or refrigerate for up to 1 hour before serving for a chilled option.