Moist Coffee Cake - Cakes by MK

Ingredients

• 2½ cups flour (regular all purpose (see note 1 if you want to use cake flour))
• ⅓ cup cornflour (also known as cornstarch)
• ½ tsp baking soda
• 1 tsp baking powder
• ½ tsp salt (omit if using salted butter)
• 4 tbsp instant coffee powder (I use a fine powdered coffee)
• ½ cup unsalted butter (room temperature)
• ½ cup unflavoured vegetable oil (I use canola)
• 1½ cups soft brown sugar (firmly packed (see note 6))
• 3 large eggs (room temperature)
• 1¼ tbsp vanilla essence/extract
• 1 tsp white vinegar
• 1½ cups buttermilk (room temperature, see note 5 if using a homemade buttermilk substitute)
• 1 cup white chocolate
• 3 cups cream (minimum fat percentage of 34%)
• 1½ tbsp instant coffee powder (I use a fine powdered coffee)
• 2 tbsp soft brown sugar
• 1 tbsp unsalted butter
• ½ tsp ground cinnamon
• 1 cup walnuts (roughly chopped or halved)