Using a small bowl, add all of the streusel ingredients (butter, brown sugar, flour, oats, walnuts and cinnamon); stir until well combined. Set streusel aside.

Using a microwave safe bowl, add cream cheese and butter; microwave on low for 30 seconds. Stir until well combined. (Note: If necessary, continue microwaving in 10 second intervals until mixture is soft enough to easily stir together.)

Add sugar, vanilla and cinnamon; stir until well combined. Place bowl in refrigerator until needed.

Line 18 muffin tin cups with paper liners, or spray with nonstick baking spray; set pan(s) aside.

Preheat oven to 400°F.

Using a large bowl, add dry ingredients (flour, sugar, brown sugar, baking powder, baking soda, cinnamon, ginger, cloves and salt); stir until well combined.

In a separate bowl, whisk together oil, eggs, milk and vanilla. Add liquid mixture to the dry mixture and stir until just combined.

Fold in carrots and raisins.

Drop 2 Tbsp of batter into each of the prepared muffin cups, spreading the batter so that it covers the bottom of each cup.

Drop ~½ Tbsp of filling into each muffin cup.

Fill the muffin cups with remaining batter until ~½” from the top. (~1 Tbsp of batter per cup.)

Using your fingers, crumble the streusel topping on top of the cups.

Bake for 18-20 minutes, or until a toothpick inserted into center of cake part of one of the muffins comes out mostly clean.

Let muffins cool in pan for 2-3 minutes before transferring to a cooling rack. (Note: If you serve the muffins warm, the filling will be loose. If you serve the muffins at room temperature, the filling will be a bit more firm.)