In a small bowl, combine the softened butter, brown sugar, and 3 teaspoons of cinnamon. Beat until smooth and creamy.

In another small bowl, combine the granulated sugar and 1 teaspoon of cinnamon. Set aside for coating.

In a shallow bowl, whisk together the eggs and milk. Set aside for dipping.

Trim the crusts from the bread slices. Using a rolling pin, flatten each slice to about 1/8 inch thickness.

Spread a generous layer of the cinnamon butter mixture evenly over each flattened bread slice.

Tightly roll up each bread slice, starting from one end and ending at the other. Secure the seam, if needed, with a tiny dab of the cinnamon butter.

Heat a non-stick pan or griddle over medium heat. Melt about 1 tablespoon of butter in the pan.

Dip each roll-up into the egg mixture, ensuring all sides are coated. Allow excess egg mixture to drip off.

Place the roll-ups seam-side down in the hot pan, cooking 3-4 at a time to avoid overcrowding. Add more butter to the pan as needed.

Cook for 2-3 minutes per side, or until golden brown and cooked through. Turn gently to brown all sides evenly.

Remove the cooked roll-ups from the pan and immediately roll them in the cinnamon-sugar mixture, coating them thoroughly.

Dust with powdered sugar, if desired. Serve warm and enjoy immediately!