Preheat oven to 350℉. Grease and flour a standard size loaf pan and set aside.
In a large mixing bowl, beat together butter, cream cheese, vanilla extract and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Continue mixing for 5 minutes until fluffy. Add the baking powder and milk and mix.
Slowly add the flour and mix until just incorporated, you don’t want to overmix it.
Divide the batter: Reserve two-thirds of the batter in the bowl. Pour the remaining one-third into a separate bowl. (The measurements don't have to be exact)
Add the raspberry jam and food coloring (if using) to the small bowl of batter, stirring to incorporate.
Pour about one-third of the plain white batter into the bottom of the prepared pan. Add one-half of the raspberry batter and continue, alternating between the two, and ending with the white batter. (There should be 5 layers: white, raspberry, white, raspberry, white)
In a small bowl combine all the streusel ingredients and mix until it resembles coarse sand. Sprinkle evenly over the cake batter.
Bake uncovered in the preheated oven for around 45-55 minutes, or until a cake tester comes out clean when inserted in the center.
Notes
Grease the loaf pan well to make removing the cake easier.
Use full fat butter and cream cheese for the best flavor and the moistest crumb.
Avoid over mixing the batter. The more you stir the flour, the more protein strands are formed. Mixing too much will cause your cake to be dry and tough.
Allow the raspberry pound cake to cool for at least 20 minutes before trying to remove it from the loaf pan.