Preheat oven to 325*F.
Lightly grease 10" tube pan.
STREUSEL: In a medium bowl, combine the brown sugar, flour, butter, and cinnamon with a fork until crumbly.
Stir in the walnuts.
POUNDCAKE: Using an electric mixer on high speed, cream together the butter, pancake syrup, brown sugar, vanilla, baking powder, baking soda, and salt in a large bowl until well blended (the mixture will look curdled).
Add the eggs, one at a time, blending well after each addition (the mixture will still look curdled).
With the mixer on low speed, gradually add the flour, beating just until blended and smooth.
Spoon 1/2 the batter into the prepared pan; sprinkle with 1/2 the streusel.
Cover with remaining batter and streusel.
Bake for 75-85 minutes, or until a toothpick inserted in the center comes out with moist crumbs clinging to it.
Cool in pan on a wire rack for 15 minutes; loosen edges of cake from sides of pan.
Carefully invert onto a wire rack; cool completely.
Store wrapped airtight at room temperature for up to 3 days.