In a small bowl, whisk together flour, sugar, baking powder, and cinnamon
Add in milk, butter, and vanilla, whisking well in between each addition
Using 14-oz (or larger) microwave-safe mugs (straight sides works best), add several spoonfuls of batter to each mug
Sprinkle with a little cinnamon sugar & add a scoop of apple pie filling
Alternate layers, ending with cinnamon sugar.
Microwave on high 1.5 - 2 minutes for a single mug or 2-3 minutes for both mugs together
Allow to cool for a couple of minutes before serving.
*Serving suggestion- top with a large helping of whipped cream