In a small saucepan, combine the water, butter, and sugar. Bring to a boil, stirring until the butter is completely melted. Remove from heat, add the flour, salt, and lemon zest and stir until combined. Place over medium heat and stir until dough becomes slightly dry and leaves a film on the bottom of the pan.

Scoop the dough into the bowl of a stand mixer fitted with a paddle attachment and let cool for 5-7 minutes. Beat the mixture on low speed, allowing it to cool some more, for a few minutes. Add the eggs one at a time, beating after each addition. Let the dough rest for 1 hour.

Remove the beignets and let drain on paper towels. Sprinkle with powdered sugar and serve immediately with strawberry sauce, if desired (recipe follows).

Combine the strawberries and sugar in a saucepan over medium heat and stir until sugar is dissolved. Add the balsamic vinegar and vanilla extract. Let the mixture simmer for about 10 minutes, stirring occasionally, until sauce coats the back of a spoon with the consistency of maple syrup. Let cool. Serve warm or cold.