Coffee, sour cream and walnut cakes

Ingredients

• Cakes
• 100 gram soft butter
• 2/3 cup (about 100g) brown sugar, loosely packed
• 3 eggs
• 50 gram sour cream
• 50 gram walnut, chopped, plus extra pieces to garnish
• 1 1/2 cup plain flour (or 1 1/4 cups gluten-free flour)
• 3 teaspoon baking powder
• 3 teaspoon fine-ground espresso or 2 tsp instant coffee
• 1 tablespoon (1-2 tbsp) milk
• Icing
• 100 gram cream cheese
• 2 tablespoon sour cream
• 1/2 cup brown sugar
• 2 tablespoon (heaped tbsp) icing sugar