In a food processor or medium sized bowl, stir together flour, baking powder, baking soda, ¼ cup sugar, and 1 tablespoon powdered sugar.
In a separate bowl, whisk together milk, oil, and melted butter.
Pour milk mixture into dry ingredients while running food processor until just incoporated. Do not overmix.
Scoop into large drop biscuits, forming 6-8 balls and place on an ungreased cookie sheet.
Bake shortcakes for 12-15 minutes or until golden brown on top. Do not overbake. The shortcakes are especially delicious when they are still a tad doughy in the middle
Rinse, remove stem, and slice the strawberries into bite-sized pieces. Sprinkle with ¼ cup (per quart) of granulated sugar and stir. Let rest for 5-10 minutes.
Whisk or use the whisk attachment of a food mixer to whip the heavy cream. Add the 2 tablespoon of powdered sugar in the final seconds of whisking.
Slice warm shortcake biscuits in half and layer with sweetened strawberries and whipped cream.