01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Combine water, milk, butter, sugar, and salt in a medium saucepan. Bring to a boil over medium heat.
03 - Remove from heat and stir in flour all at once. Return to heat and cook, stirring vigorously, until dough forms a ball and pulls away from sides, about 2 minutes.
04 - Transfer dough to a mixing bowl and let cool for 5 minutes. Beat in eggs one at a time, mixing well after each addition, until dough is smooth and glossy.
05 - Spoon dough into a piping bag fitted with a large round tip. Pipe 4-inch long strips onto prepared baking sheet, spacing about 2 inches apart.
06 - Bake for 20 minutes, then reduce oven temperature to 350°F and bake for another 15 minutes until golden and crisp. Cool completely on a wire rack.
07 - Whisk together lemon juice, zest, sugar, and eggs in a heatproof bowl. Set over a simmering pot of water and whisk constantly until thickened, about 8 minutes.
08 - Remove from heat and whisk in butter until smooth. Chill until cold. Whip heavy cream to stiff peaks, then gently fold into chilled lemon curd.
09 - Slice cooled éclairs in half horizontally. Pipe or spoon lemon cream onto bottom halves. Add fresh raspberries, then cover with top halves.
10 - Whisk together powdered sugar, lemon juice, and zest until smooth and pourable. Spread or drizzle over tops of éclairs.
11 - Chill éclairs for at least 30 minutes before serving to allow filling to set.