In a medium saucepan, bring 1 cup of water and ½ cup of butter to a boil over medium heat until melted. Stir in 1 cup of all-purpose flour swiftly until a smooth dough forms, cooking for about 2 minutes until it pulls from the sides of the pan. Remove from heat and let it cool slightly before mixing in 4 eggs one at a time until the mixture is glossy and smooth.

Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper. Pipe the choux pastry into 4-inch oblong shapes, leaving space between each. Bake for 25-30 minutes or until puffed and golden brown. Allow eclairs to cool inside the oven for 10 minutes before transferring them to a wire rack to cool completely.

In a mixing bowl, whip 1 cup of heavy cream, ½ cup of sugar, the zest of 1 lemon, and 2 tablespoons of lemon juice until thickened and soft peaks form, approximately 3-5 minutes. Fill a piping bag fitted with a small round tip. Once the eclairs are completely cooled, poke a hole in the side of each eclair and fill with the lemon cream.

In a small saucepan over medium heat, combine 1 cup of raspberries and ¼ cup of sugar. Cook until the raspberries break down and the mixture reduces slightly, about 5-7 minutes. Strain through a sieve to remove seeds, then mix the smooth pulp with 1 cup of powdered sugar until glossy.

Dip the tops of each filled lemon eclair into the raspberry glaze, letting the excess drip off. Place the glazed eclairs on a serving platter and allow them to set for about 10 minutes before serving.