For the doughnuts: In a medium saucepan, combine the butter, water, sugar, and salt over medium heat. Bring to a rolling boil, stirring occasionally.
Boil for 10 seconds. Remove the pan from the heat and add the flour. Using a wooded spoon, quickly stir the mixture until all the flour is fully incorporated and forms a thick dough. Return the pan to the heat and stir continuously for 2 minutes. Scrape the mixture into a stand mixture fitted with a paddle attachment. With the machine running on medium speed, add the eggs and egg yolk, one at a time until fully incorporated. Beat the mixture for 4 to 5 minutes until thick and glossy. Add the lemon zest and beat until smooth. Refrigerate the dough for 15 minutes.
For the glaze: In a medium bowl, whisk together the cream, coffee liqueur, vanilla, and espresso powder until smooth. With a wooden spoon, gradually stir in the powdered sugar until smooth. If the glaze is too thick, stir in the water, 1/4 teaspoon at a time.
In a large heavy-bottomed saucepan, pour enough oil to fill the pan about a third of the way. Heat over medium heat until a deep-frying thermometer inserted in the oil reaches 375 degrees F. (If you don't have a thermometer a cube of bread will brown in about 3 minutes.)
Using a small ice cream scoop or two small spoons, carefully drop about 1 tablespoon of the dough into the oil. Cook for 3 to 3 1/2 minutes, turning occasionally, until the zeppole is golden and puffed. Drain on paper towels.
When the zeppole is cool enough to handle, dip the top halves in the glaze.
Using a hand grater, grate the chocolate over serving plates. Place 3 to 4 zeppole on each plate and garnish with fresh raspberries. Serve immediately.