Step 1: Prepare the Oven

Preheat your oven to 350°F. Grease a 9-inch square baking pan

Step 2: Toast the Pecans

Spread the chopped pecans on a baking sheet and bake for 5–7 minutes, stirring once, until fragrant. Let them cool slightly.

Step 3: Make the Streusel

In a medium bowl, combine the toasted pecans, brown sugar, flour, cinnamon, and salt.

Stir in the vanilla and melted butter until crumbly. Set aside.

Step 4: Make the Batter

In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon.

In a large mixing bowl, beat the butter and granulated sugar until light and fluffy, about 3–4 minutes.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Mix in half of the dry ingredients, followed by the sour cream, then add the remaining dry ingredients. Mix just until combined.

Step 5: Assemble

Spread half of the batter into the prepared pan.

Sprinkle about half of the streusel evenly over the batter.

Spread the remaining batter on top, then finish with the remaining streusel.

Step 6: Bake

Bake for 40–50 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the cake cool in the pan for about 20 minutes.

Step 7: Glaze

Whisk together the powdered sugar, milk, and vanilla until smooth.

Drizzle the glaze over the slightly warm or completely cooled cake.