Cardamom Crumb Cake

INGREDIENTS

• 1/2 cup whole milk
• 1 teaspoon instant espresso powder
• 1/4 teaspoon salt
• 1 1/2 teaspoon pure vanilla extract
• 1/2 tablespoon stick (4 tablespoons) unsalted butter, cut into 8 pieces, at room temperature
• 1/2 teaspoon instant espresso powder
• 2 tablespoons finely grated orange zest
• 1/2 cup strong coffee, cooled
• 1/3 cup sugar
• 1/2 teaspoon ground cardamom
• 1 1/4 teaspoon ground cardamom
• 1 tablespoon grated orange zest
• 2 cups all-purpose flour
• 2 large eggs
• 1/2 cup coarsely chopped walnuts
• 1/2 cup all-purpose flour
• 2 teaspoons baking powder
• 1 stick (8 tablespoons) unsalted butter, melted and cooled
• 2/3 cups sugar