Fluffy Pistachio Coffee Cake with Sweet Streusel Topping - Yummy Gusto

Ingredients

• 1 cup (200g) packed light brown sugar
• 1 1/2 teaspoons ground cinnamon
• 2/3 cup (150g) finely chopped pistachios
• 1/2 cup (113g) unsalted butter
• 1 1/4 cups (150g) plain flour
• 2 teaspoons baking powder
• 1 tablespoon coffee grounds
• 1 3/4 cups (210g) all-purpose flour
• 1/2 cup (110g) whole milk, at room temperature
• 3 tablespoons (45g) sour cream, soft at room temperature
• 1/2 teaspoon salt
• 9 tablespoons (125g) unsalted butter, softened
• 1 1/2 teaspoons real vanilla
• 2 large eggs, warmed to room temp
• 3/4 cup plus 2 tablespoons (175g) regular sugar
• 1 tablespoon strong espresso
• 1/2 cup (60g) sifted powdered sugar