Log4net - display full exception information including inner exception(s)

Our log4net (config below) gives us the Exception.Message, but that's all. I need it to log the stack trace and all inner exceptions, with the stack trace for each of those.

How do I do this?

<log4net>
    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
        <param name="File" value="C:/temp/AutoTag_Word.log"/>
        <param name="AppendToFile" value="true"/>
        <param name="MaxSizeRollBackups" value="10"/>
        <param name="MaximumFileSize" value="1000KB"/>
        <param name="RollingStyle" value="Size"/>
        <param name="StaticLogFileName" value="true"/>
        <layout type="log4net.Layout.PatternLayout">
            <param name="ConversionPattern" value="%d [%t] ac.server %-5p %c - %m%n%exception"/>
        </layout>
    </appender>
    <root>
        <level value="DEBUG"/>
        <appender-ref ref="RollingFileAppender"/>
    </root>
    <logger name="WindwardArrow.net.windward.arrow.datasource.ado">
        <level value="DEBUG"/>
    </logger>
</log4net>

This works:

Add our custom log formatter.

Use the below:

<log4net debug="false">
    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
        <param name="File" value="C:\temp\CleanTemplates.log" />
        <param name="AppendToFile" value="true" />
        <param name="MaxSizeRollBackups" value="2" />
        <param name="MaximumFileSize" value="50KB" />
        <param name="RollingStyle" value="Size" />
        <param name="StaticLogFileName" value="true" />
        <layout type="Kailua.net.windward.utils.ExceptionFormatter">
            <param name="ConversionPattern" value="%date [%thread] %level %logger - %message%newline%exception" />
        </layout>
    </appender>
    <root>
        <level value="debug" />
        <appender-ref ref="RollingFileAppender" />
    </root>
</log4net>