Beat the butter with the sugar for 3 to 4 minutes until the mixture is pale and creamy.
Add the eggs and beat until they are mixed in.
Add the sour cream and the vanilla extract to the mixture and mix until everything is combined.
Combine the flour, baking powder, pumpkin spice, and salt.
Add the dry ingredients to the cake batter, stirring gently until just combined.
Spoon the cake batter into a buttered 8-inch square cake pan and level out the top.
Bake the cake for 40 minutes or until it appears golden and springs back when touched.
Cool the cake completely, then crumble it until it resembles breadcrumbs.
In a mixing bowl, combine the frosting with the cake crumbs until the mixture can be formed into a ball.
Roll heaping teaspoons of crumb mixture into round balls.
Refrigerate the cake balls for at least 30 minutes to set.
Remove cake balls from fridge. Using a lollipop stick, make several indents that reach from top to bottom along each cake ball to give it the appearance of a pumpkin.
Melt the chocolate in a microwave or pan, stirring frequently to ensure that it will not burn.
Stir a few drops of food coloring into the melted chocolate.
Working one at a time, dip the end of each lollipop stick into the melted chocolate and then immediately and gently press it into the bottom of each pumpkin cake ball.
Cool the cake balls, stick-side up, for at least 10 minutes.
Once the sticks are set, dip each pop into the melted chocolate to cover, then let the excess drip off.
Place the cake pops to cool, pop-side up (a tall glass can make for a good cooling rack).
Before they cool completely, press a pretzel chunk into the top of each cake pop to resemble the pumpkin stem.
Let the cake pops set for at least 10 more minutes before eating.