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 pan sides, about 2 minutes.
04 - Transfer dough to a mixing bowl and cool for 5 minutes. Beat in eggs one at a time, mixing thoroughly after each addition, until smooth and glossy.
05 - Spoon dough into a piping bag fitted with a large round tip. Pipe 4-inch strips onto prepared baking sheet, spacing 2 inches apart.
06 - Bake at 400°F for 20 minutes, then reduce temperature to 350°F and bake 15 minutes longer until golden and crisp. Cool completely on a wire rack.
07 - Whisk lemon juice, zest, sugar, and eggs in a heatproof bowl. Set over simmering water and whisk constantly until thickened, about 8 minutes.
08 - Remove from heat and whisk in butter until smooth. Refrigerate until cold.
09 - Whip heavy cream to stiff peaks. Gently fold into chilled lemon curd until combined.
10 - Slice cooled éclairs horizontally. Pipe or spoon lemon cream onto bottom halves. Add fresh raspberries and cover with top halves.
11 - Whisk powdered sugar, lemon juice, and zest until smooth and pourable.
12 - Spread or drizzle glaze over éclair tops. Refrigerate at least 30 minutes before serving to set filling.