In a large bowl, whisk together Bisquick, milk, eggs and vanilla. Pour batter into a freezer ziplock bag, or squeeze bottle with a large opening if you have one. Set aside for now.
Depending on the size of your skillet, pour oil about 1 inch deep. Begin to heat over medium heat. Cut the corner off of your ziplock bag and squeeze 1 drop of batter into the oil to see if it's hot enough. If it fries immediately it's hot enough.
Create the form of a funnel cake by squeezing batter in a circular motion in oil. (I made one funnel cake at a time). Fry for 30-45 seconds on each side, or until golden brown.
Carefully remove the funnel cake from the oil and place on a paper towel lined plate to drain any excess oil. Repeat with remaining batter. Once the funnel cakes have cooled slightly, sprinkle powdered sugar over the top and spoon pie filling over that to serve.