In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda, and salt.
In a separate medium bowl, whisk together the buttermilk, egg, melted butter, and 1/2 teaspoon vanilla extract until combined.
Pour the wet ingredients into the dry ingredients and gently stir until just combined. Do not overmix; a few lumps are okay.
In a small bowl, combine the softened cream cheese, powdered sugar, and 1/2 teaspoon vanilla extract. Mix until smooth and creamy.
Gently fold the finely chopped strawberries into the cream cheese mixture.
Preheat a non-stick skillet or griddle over medium heat and lightly coat with cooking spray.
Using a tablespoon, pour about 1 tablespoon of pancake batter onto the skillet to form small circles.
Immediately place about 1 teaspoon of the strawberry cream cheese filling in the center of each batter circle.
Top each filled batter circle with another tablespoon of pancake batter, covering the filling completely and sealing the edges gently with the back of the spoon.
Cook the pancake poppers for 2-3 minutes on the first side, until bubbles form on the surface and the edges look set.
Carefully flip each popper and cook for an additional 2-3 minutes on the other side until golden brown and cooked through.
Remove from the skillet and repeat with the remaining batter and filling, spraying the skillet as needed.
Serve warm, optionally dusted with powdered sugar or drizzled with maple syrup.