Preheat the oven to 350°F (175°C) and grease a 9x13 inch baking pan.

In a medium bowl, combine the oatmeal, flour, baking powder, and salt. Whisk together.

In a large mixing bowl, cream the butter and brown sugar until light and fluffy, about 3-5 minutes.

Add the eggs and vanilla extract to the creamed mixture and mix until combined.

Gradually add the dry mixture to the wet ingredients and stir until just combined.

In a saucepan over low heat, combine chocolate chips, sweetened condensed milk, and butter. Stir until melted and smooth.

Press half of the oatmeal mixture into the greased pan, pour over the chocolate fudge, then crumble the remaining oatmeal mixture on top.

Bake for approximately 25 minutes until the top is lightly browned. Allow to cool in the pan for at least 30 minutes.

Once cooled, cut into squares and store properly.