Heat a griddle to 350 degrees. Mix the milk, egg, sour cream, and vanilla until smooth in a large bowl. Sift the flour, baking soda, sugar and salt together in a smaller bowl. Add the dry mixture to the wet mixture until just combined. The batter may be lumpy. Pour 1/4 cup batter onto the griddle, cooking until bubbles rise in the center. Flip pancakes and cook the other side until golden brown. Repeat with the remaining batter. Serve with your favorite pancake toppings. Tip: for a festive occasion, add food coloring to the batter before cooking. Tip 2: to make holiday shapes, spray metal cookie cutters with non-stick cooking spray or canola oil and pour batter into shapes. Flip the cookie cutters with tongs (they will be hot) until the second side is done. Carefully remove cookie cutters with tongs.