Preheat the oven to 350°.

Cream together the butter and granulated sugar in the bowl of a stand mixer or in a large bowl with an electric hand mixer. Mix for 2 minutes.

Scrape the sides of the bowl and add in the eggs and vanilla. Mix until well combined.

Add in the flour and baking powder. Start mixing and when the flour is about halfway combined, pour in the canola oil. Mix until the dough comes together.

In a small bowl, combine the brown sugar, cinnamon and flour with a fork. Set aside.

In a separate small bowl, whisk together the egg and milk to make the egg wash. Set aside.

Portion out the dough in to ⅓ cup portions.

Work with one portion at a time. Split the portion in half, press one portion of the dough in the palm of your hand until it is flat and about 3 inches in diameter.

Brush the dough with the egg wash.

Spoon approx 2 teaspoon of the filling mixture into the center of the cookie dough. Spread it over the cookie dough, leaving a border around the edge.

Flatten the second portion of the dough In your hand until it is 3 inches in diameter. Place it on top of the cinnamon brown sugar mixture.

Use a fork to gently crimp the edges of the cookie.

Brush with the egg wash.

Repeat with remaining dough.Bake at 350 for 11-14 minutes, until the edges turn golden brown.

Allow the cookies to cool on the pan while you make the icing.

To make the icing, combine the butter and ¼ cup of powdered sugar until smooth.

Add the rest of the powdered sugar and heavy cream. Mix until smooth.

Stir in the cinnamon and vanilla.

Whisk in milk, 1 tablespoon at a time until you have your desired thin consistency.

Spoon onto the center of each cookie and spread to cover.

Serve warm or room temperature.