Easy Coffee Cake Recipe

Combine the egg, avocado or vegetable oil, vanilla, whole milk, salt, and sugar in a bowl and mix. Sprinkle 1 1/2 cup flour and 2 tsp baking powder on top of the wet mixture. Mix only the top layer first, then fully incorporate it into the batter until just combined. For the topping, mix together 2 tbsp melted butter, 1/2 cup brown sugar, 2 tsp cinnamon, and 2 tbsp flour until crumbly. Spread the coffee cake batter into a prepared baking dish, then sprinkle the topping evenly over the batter. Bake at 375°F (190°C) for 25-30 minutes, or until a toothpick inserted into the center comes out clean.