THE ULTIMATE PEANUT BUTTER WHOOPIE PIE

Steps:

• Heat oven to 425°F Prepare baking sheet by greasing with shortening. Prepare countertops for cooling pies by lining with sheets of foil.
• PIES:.
• In small microwavable bowl, mix together 1 cup milk and vinegar. Microwave at HIGH to warm slightly (you may also achieve this in a small saucepan on a stove top on medium heat). Mixture will appear separated and curdled.
• In large bowl combine granulated and brown sugars, and crunchy peanut butter. Beat at medium speed with electric mixer until crumbly.
• Add ½ cup shortening to 2-cup glass measure. Pour boiling water over and stir to melt shortening. Add to peanut butter mixture along with milk mixture and vanilla. Beat at low speed. Mixture will appear very fluid and a tad separated.
• Combine 4 cups flour, cocoa, baking soda, baking powder and salt. Stir well. Add all at once to peanut butter mixture. Beat at low speed until mixture is blended and resembles thick cake batter. Allow to stand 20 minutes. Drop by rounded measuring tablespoonfuls 2 inches apart onto prepared baking sheet.
• Bake in upper half of oven for 8 to 10 minutes or until set TAKING CARE NOT TO OVERBAKE. Allow to cool 2 minutes on baking sheet. Transfer pies to foil and cool completely.
• FILLING:.
• Combine ½ cup milk and 3 tablespoons flour in small saucepan. Cook and stir on medium heat until thickened. Allow to cool completely. Transfer to medium bowl and add confectioners' sugar, ½ cup shortening, creamy peanut butter and vanilla. Beat at low speed until blended. Beat at high until smooth. Refrigerate until ready to use. Spread filling on bottom halves of pies. Top with remaining pie halves. Press together gently.