In a medium saucepan, combine 1 cup of filtered water and ½ cup of butter over medium heat. Bring the mixture to a boil and stir in 1 cup of all-purpose flour and a pinch of salt until a smooth dough forms. Allow to cool for about 5 minutes, then whisk in 4 eggs, one at a time.

Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper. Using a piping bag, pipe 4-inch long strips of the dough on the prepared sheet. Bake for 25-30 minutes until golden brown.

Remove the eclairs from the oven and transfer them to a wire rack. Allow to cool completely, at least 30 minutes.

While cooling, whip 1 cup of heavy cream with ½ cup of powdered sugar and the zest and juice of 2 lemons until soft peaks form. Chill for about 15 minutes.

Pierce the sides of each cooled eclair and fill them with the chilled lemon cream using a piping bag.

Combine ½ cup of raspberry puree with 1 cup of powdered sugar until smooth and glossy. Adjust consistency as needed.

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