Preheat your oven to 350°F (177°C).

In a large mixing bowl, combine 1/2 cup softened butter, 1/2 cup vegetable oil, and 1 cup brown sugar. Beat until light and fluffy.

Crack in 1 large egg and add 1 tsp of vanilla extract. Mix until well blended.

Gradually add 2 tsp cinnamon, 1/2 tsp baking soda, 1/2 tsp baking powder, 1/2 tsp salt, and 2 1/2 cups all-purpose flour. Fold until combined.

In a separate bowl, mix 1/4 cup softened butter, 1/4 cup brown sugar, 1/3 to 1/2 cup flour, 1/2 tsp cinnamon, and a pinch of salt until crumbly.

Drop balls of cookie dough onto your baking sheet, spacing them about 2 inches apart. Make an indent in the center of each ball.

Generously fill the indents with streusel mixture.

Bake for 10-12 minutes or until edges are golden.

Whisk together 1/2 cup powdered sugar, 1 tbsp milk, and a splash of vanilla extract until smooth for icing.

Drizzle icing over cooled cookies.